A simple solution for alpha channel hacks - ignore them :).

The 'ignore ARGB visuals' option from Kompmgr probably doesn't make much sense, those (usually old) apps can be run with XLIB_SKIP_ARGB_VISUALS=1 set.

Also remove the alpha clear hack used for decorations - I think decorations instead should be fixed not to "unintentionally" have alpha set.