Since we are going to release a new major version, we may also do some bigger refactoring changes in the process. (I would release v3.14 as the last version for all).
In general there are some things, we should improve:

• A lot of top level files. We may just remove some files and move the ST related files to an extra directory.
• Reformat the files. The python files should have the same format (and names) according to PEP8 and not a mix from the styles of different people. The json files should also have a sane format (no mix of tabs and spaces, etc.).
• Start time: LaTeXTools has a huge load-time at the startup of ST, because it has many modules and ships it own plugin system. Since ST is not only a LaTeX-editor, we should try to decrease that time, e.g. by just loading the builder, if a tex file is opened.

Incompatible changes

• rename Sublime Text commands to fit the naming guide line Deprecate old commands for common naming schema #1423
• prefix view settings with latextools. to avoid collusion with other packages Prefix view settings with latextools. #1467

Refactoring

• move sublime-* files into an extra directory.
• remove outdated files
  • *.OLD
  • Symbol List.tmPreferences
• remove conditional loader (for preview), because we don't need it any more
• remove and join some python files
• Reformat python files to fit PEP8 (4 spaces indent)
• Reformat Keybindings
• Rename release messages. Just rename them e.g. from 40d.txt to v3.13.4.txt

Improvements

• Lazy load. LaTeXTools needs a relative big time on ST startup. We may somehow change the loader to lazy load stuff (e.g. builder, viewers), when the first tex file is opened, to improve the startup time.

Features

We should also add some features (the release info should not just be "some internal improvement"). However some of those may be postponed to a 4.x release:

• insert math popup Popup for quick and easy insertion of symbols inside math environments #1111
• User entered text in quickpanel Feature Request: Allow fill all quick panel to use user-entered text #1051 , Added a quickpanel, which is able to input characters #1118
• Rename command Feature Request: "Refactor/Rename Label" #1103
• auto-insert label contents Add a command to automatically insert label contents #1131
• TikZ/PGF support Support for TikZ/PGF #1079