v1.2: Control Focus, mode menu tweaks

Also some bug fixes, removed fudge factors in various places etc.

Signed-off-by: Michel Pollet <[email protected]>

Version 1.1, moar stuff added.

See the CHANGELOG.md for details.
* Added support for horizontal scrollbars.
* Added a faster (vectorized) version of an obvious 'cg' function.
* Fixed a problem with mui_timers. Also typed it now.
* Added a bunch of extra comments to mui.h
* Added a *fully justified* text style for text boxes.

Signed-off-by: Michel Pollet <[email protected]>