Merge pull request n4n0GH#61 from sergiofenoll/master

Adds build dependencies for openSUSE

fix n4n0GH#44

added option to never show window button icons on hover

fixed n4n0GH#27 rect to redraw titlebar was set way too large

hotfix for close button showing a way too bright icon on hover

fixed n4n0GH#26

added option to only use button icons as per RFC n4n0GH#25

fixed build issue n4n0GH#23

updated decoration README with ubuntu PPA instructions