* Keep pressed keys on layer state change
* Add doc comment for clear_keyboard_but_mods_and_keys
* Keep pressed keys only if PREVENT_STUCK_MODIFIERS is on
* Check STRICT_LAYER_RELEASE instead of PREVENT_STUCK_MODIFIERS
* Remove chording as it is not documented, not used, and needs work.
* Make Leader Key an optional feature.
* Switch from `PREVENT_STUCK_MODIFIERS` to `STRICT_LAYER_RELEASE`
* Remove `#define PREVENT_STUCK_MODIFIERS` from keymaps.
* Generate api docs from source code
* Add a bunch of doxygen comments
* more doxygen comments
* Add the in-progress api docs
* script to generate docs from travis
* Add doc generation to the travis job
* make travis_docs.sh commit the work it does
* make sure the docs script exits cleanly