This patch adds an optional texture cache to the blur effect such that damaged windows in
front of the blurred region dont trigger a repaint of the whole blurred region which pretty
often results in a avalanche repaint of nearly the whole screen.
REVIEW: 101977
Each effect is able to declare itself as currently being active,
that is transforming windows or painting or screen or doing anything
during the current rendered frame.
This change eliminates the hottest path inside KWin identified by
callgrind.
REVIEW: 102449
its own directory, cleaned up the effect config macros and renamed
"MakeTransparent" to "Translucency" so that it matches its visible name.
svn path=/trunk/KDE/kdebase/workspace/; revision=921749