Allow selecting any number of standard and custom layouts.
Allow adding custom keys to the keyboard.
Changed behavior of auto-added keys (often dead-keys).
New layouts.
Improved layouts and language support.
Improved the space bar slider, and many more.
Updated translations.

Thanks to the contributors: @ChasmSolacer, @ElucGeek, @GoRaN909, @RZHSSNZDH, @Shareef101, @Validbit, @eandersons, @nitsvga, @polyctena, @sdrapha, @syskill
