Added platform interface.
corrections
Added a cast to keycodes for modifier matching
Some progress for XCB implementation
Fixed qt4 crash, again.
Fixed lock modifier issue.
Added base comments
sandkeys-qt5 and sandkeys-qt4 can be dragged by clicking the background.
added close button
added minimize button for Qt4
Added minimize button for Qt5
Changed 'implicit' scale for Qt4 theme
added transparency for qt4.
Corrected a bug for Meta modifier.
Misc improvements for Qt4 theme.
Added trasparency for both Qt4 and Qt5.