fix infobar colors

Closes: #2
remove mist stuff for inactive menus, it was making them bland

See: #3 and #1
fix hilighting of panel items

See: #3
fix warnings in murrine

this removes the warning, but doesn't fix the scrollbar colors, which
are a bit off, for example

See: #1
switch from murrine to XFCE theme

this is because murrine hasn't been updated in two years and to reduce dependencies as I'm using xfce now..

See: #1
outline buttons properly
mention xfce-dusk as a source
Merge pull request #4 from anarcat/master

fix background colors on info boxes and general hilighting
Thanks for all the awesome commits @anarcat