Creating an EffectFrame requires I/O which takes on my system
during testing between 10 and 40 msec. Also it needs a little
bit of memory.
This changes moves out the creation of EffectFrames at Effect
load till the Effect actually needs the EffectFrame. E.g. if a
user does not filter in PresentWindows there is no need to ever
create it.
BoxSwitch effect is ignored as it should be dropped for 4.9.
REVIEW: 104815
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
