- menue: allow icon-only menu hints
- keyboard_input: auto calculate size of input-field ...

  ... if size is 0 or not given.
- align most CKeyboardInput calls to the changes in 88c6640
Revert "- plugins: allow empty menu hints"

This reverts commit 95eab2a48d2b58e1fae67af60f6ec58e4dcd3c72
because 9945d0348039b2ec5e7927b7e91ce8ac251c97ed do the same.
Merge remote-tracking branch 'cool-cst-next/cst-next'

Conflicts:
	src/gui/moviebrowser.cpp