Second part of cleaning up the lib directory: the effects library
now lives in libkwineffects/ directory.
For existing effects nothing changes as the install path is unchanged.
The change obsoletes the lib/ directory.
As glplatform.h has not yet been exported I dared to export it and
adjust the places where it is used.
CCMAIL: kwin@kde.org
GUI panel. This panel is currently located in System Settings -> Desktop
-> Screen Edges.
BUG: 174709
svn path=/trunk/KDE/kdebase/workspace/; revision=932929
