Return lists of last-resort font family names in platform-specific font_list code, so that they can be appended to the end of FontGroup and used if the requested font faces are not available.

Add get_image_properties() to resource cache.

This allows querying image opacity before an image is added to
the texture cache.

This doesn't change functionality, but it's prep work for some
of the upcoming interface changes in the resource cache that are
needed for subpixel glyph functionality.

This is arguably a much cleaner interface as well, it never really
made sense to have this accessible only via the texture cache.

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Bump cbindgen from 0.14.1 to 0.14.2

Bumps [cbindgen](https://github.com/eqrion/cbindgen) from 0.14.1 to 0.14.2.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/eqrion/cbindgen/blob/master/CHANGES">cbindgen's changelog</a>.</em></p>
<blockquote>
<h2>0.14.2</h2>
<pre><code> * Fixed minimal dependency versions. ([#507](mozilla/cbindgen#507))
 * Add an option to write pragma once. ([#511](mozilla/cbindgen#511))
 * Fix submodule scanning for implicit Rust 2018 modules. ([#512](mozilla/cbindgen#512))
 * Fix dependency parsing / scanning to handle target-specific versions. ([#513](mozilla/cbindgen#513))
 * Use heck for case conversion. ([#514](mozilla/cbindgen#514))
 * Add support for verbatim content after includes. ([#416](mozilla/cbindgen#416))
 * Allow to add attributes to most generated functions. ([#515](mozilla/cbindgen#515))
</code></pre>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/eqrion/cbindgen/commit/b6b88f8c3024288287368b377e4d928ddcd2b9e2"><code>b6b88f8</code></a> Release v0.14.2</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/a05a223704e206679068cf84da09a7b49ea202a4"><code>a05a223</code></a> tests: Add tests for attribute annotations.</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/5ee5b3ee8884b256decf6e4d91563799a986d758"><code>5ee5b3e</code></a> ir: Allow per-method annotations for all the auto-generated struct and enum m...</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/be8e6ec876972b28519803e041ae12b4c63948fc"><code>be8e6ec</code></a> enum: Allow to store annotations for empty variants.</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/1a824c04f21f22d1488609cedf8d0c7b13bb83eb"><code>1a824c0</code></a> Add support for verbatim content after includes</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/d0d67165561c6249d39148bc1b63d62d713fdd1a"><code>d0d6716</code></a> ir: Minor cleanup to the cfg code.</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/8139fbf3c7db6e0635161ecc5631d865ac4e3d4e"><code>8139fbf</code></a> Fix <a href="https://github-redirect.dependabot.com/eqrion/cbindgen/issues/418">#418</a>: Use heck for case conversion</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/4beb526516fa6e1de38cebc3f02b1d095f8947d1"><code>4beb526</code></a> Fix <a href="https://github-redirect.dependabot.com/eqrion/cbindgen/issues/254">#254</a> (<a href="https://github-redirect.dependabot.com/eqrion/cbindgen/issues/512">#512</a>)</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/ca1c0b27b66edc372d7c190e8d22e41125a985a4"><code>ca1c0b2</code></a> Run cargo-fmt</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/1df5129d1a227d5f1dbf66b6d8fe66eba44ae880"><code>1df5129</code></a> Fix 2015 edition module path resolution</li>
<li>Additional commits viewable in <a href="https://github.com/eqrion/cbindgen/compare/v0.14.1...v0.14.2">compare view</a></li>
</ul>
</details>
<br />

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Bump cbindgen from 0.14.1 to 0.14.2

Bumps [cbindgen](https://github.com/eqrion/cbindgen) from 0.14.1 to 0.14.2.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/eqrion/cbindgen/blob/master/CHANGES">cbindgen's changelog</a>.</em></p>
<blockquote>
<h2>0.14.2</h2>
<pre><code> * Fixed minimal dependency versions. ([#507](mozilla/cbindgen#507))
 * Add an option to write pragma once. ([#511](mozilla/cbindgen#511))
 * Fix submodule scanning for implicit Rust 2018 modules. ([#512](mozilla/cbindgen#512))
 * Fix dependency parsing / scanning to handle target-specific versions. ([#513](mozilla/cbindgen#513))
 * Use heck for case conversion. ([#514](mozilla/cbindgen#514))
 * Add support for verbatim content after includes. ([#416](mozilla/cbindgen#416))
 * Allow to add attributes to most generated functions. ([#515](mozilla/cbindgen#515))
</code></pre>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/eqrion/cbindgen/commit/b6b88f8c3024288287368b377e4d928ddcd2b9e2"><code>b6b88f8</code></a> Release v0.14.2</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/a05a223704e206679068cf84da09a7b49ea202a4"><code>a05a223</code></a> tests: Add tests for attribute annotations.</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/5ee5b3ee8884b256decf6e4d91563799a986d758"><code>5ee5b3e</code></a> ir: Allow per-method annotations for all the auto-generated struct and enum m...</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/be8e6ec876972b28519803e041ae12b4c63948fc"><code>be8e6ec</code></a> enum: Allow to store annotations for empty variants.</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/1a824c04f21f22d1488609cedf8d0c7b13bb83eb"><code>1a824c0</code></a> Add support for verbatim content after includes</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/d0d67165561c6249d39148bc1b63d62d713fdd1a"><code>d0d6716</code></a> ir: Minor cleanup to the cfg code.</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/8139fbf3c7db6e0635161ecc5631d865ac4e3d4e"><code>8139fbf</code></a> Fix <a href="https://github-redirect.dependabot.com/eqrion/cbindgen/issues/418">#418</a>: Use heck for case conversion</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/4beb526516fa6e1de38cebc3f02b1d095f8947d1"><code>4beb526</code></a> Fix <a href="https://github-redirect.dependabot.com/eqrion/cbindgen/issues/254">#254</a> (<a href="https://github-redirect.dependabot.com/eqrion/cbindgen/issues/512">#512</a>)</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/ca1c0b27b66edc372d7c190e8d22e41125a985a4"><code>ca1c0b2</code></a> Run cargo-fmt</li>
<li><a href="https://github.com/eqrion/cbindgen/commit/1df5129d1a227d5f1dbf66b6d8fe66eba44ae880"><code>1df5129</code></a> Fix 2015 edition module path resolution</li>
<li>Additional commits viewable in <a href="https://github.com/eqrion/cbindgen/compare/v0.14.1...v0.14.2">compare view</a></li>
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</details>
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Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`.

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