By default, the runlog will always collect at LevelFilter::Debug level.
The users' choice determines what gets printed to the console.

Also, rename the lib to 'aperf'. This will allow us to use the
CARGO_CRATE_NAME when creating the logger.

Signed-off-by: Luke Robison <[email protected]>

Add error message to compile when Node is missing

This is in preparation for adding rules for SystemInfo and CPU
Utilization.

Form the metrics which will be used by the front-end for analytics work.
Generate it for SystemInfo and CPU Utilization.

Move to using JSON to hold the event details for Perf Stat. This makes
it easier to modify the files without the need for interacting with the
Rust compiler.

This is also in preparation for allowing the user to specify a custom
PMU config file.

Allow the user to specify a custom PMU file to be used during aperf
record. This custom PMU file must be in the expected format.

To aid in the creation of the custom PMU file, add a sub-command.

'aperf custom-pmu' - an interactive sub-command to create custom PMU.
This allows the user to create a file from scratch or modify an existing
PMU config aperf already knows about. The custom file generated can be
used by specifying '--pmu-config' with 'aperf record'.

Additionally, a pmu-config file can be verified by specifying --verify
along with --pmu-file with 'aperf custom-pmu'.