immediately on the server

immediately, we don't yet have the API in core to make plugins
query the window shape through compiz.

(LP: #1089279)

It was causing a critical rendering regression (LP: #1089279).

It also caused a second strange regression where it was no longer possible
to safely revert 3513 (!?) without a causing a more severe regression of
LP: #1087193.

the other times

in the right order

the interface that clients will actually need

immediately release the buffer.

[ RUN      ] ConfigureRequestBuffer.QueryAttributesDispatchAndRearm
[       OK ] ConfigureRequestBuffer.QueryAttributesDispatchAndRearm (0 ms)

This class provides the buisness logic responsible for inhibiting calls to
XConfigureWindow until an appropriate time to do so. It provides an interface
for callers to both add a pending configure to the queue but also to "lock" the
queue and prevent XConfigureWindow from being called for the most recent
configure data until those callers are ready for the queue to be released.

There are some operations which should bypass the locking behaviour directly
such as window restacks and resizes where we have a custom shape.

[==========] Running 10 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 10 tests from ConfigureRequestBuffer
[ RUN      ] ConfigureRequestBuffer.PushDirectUpdate
[       OK ] ConfigureRequestBuffer.PushDirectUpdate (0 ms)
[ RUN      ] ConfigureRequestBuffer.PushUpdateLocked
[       OK ] ConfigureRequestBuffer.PushUpdateLocked (0 ms)
[ RUN      ] ConfigureRequestBuffer.PushCombinedUpdateLocked
[       OK ] ConfigureRequestBuffer.PushCombinedUpdateLocked (0 ms)
[ RUN      ] ConfigureRequestBuffer.UnlockBuffer
[       OK ] ConfigureRequestBuffer.UnlockBuffer (0 ms)
[ RUN      ] ConfigureRequestBuffer.ForceImmediateConfigureOnRestack
[       OK ] ConfigureRequestBuffer.ForceImmediateConfigureOnRestack (0 ms)
[ RUN      ] ConfigureRequestBuffer.ForceImmediateConfigureOnShapedWindowSizeChange
[       OK ] ConfigureRequestBuffer.ForceImmediateConfigureOnShapedWindowSizeChange (1 ms)
[ RUN      ] ConfigureRequestBuffer.RearmBufferLockOnRelease
[       OK ] ConfigureRequestBuffer.RearmBufferLockOnRelease (0 ms)
[ RUN      ] ConfigureRequestBuffer.NoRearmBufferLockNoReleaseRequired
[       OK ] ConfigureRequestBuffer.NoRearmBufferLockNoReleaseRequired (0 ms)
[ RUN      ] ConfigureRequestBuffer.RearmWhenPushReady
[       OK ] ConfigureRequestBuffer.RearmWhenPushReady (0 ms)
[ RUN      ] ConfigureRequestBuffer.NoRearmBufferLockOnNoRelease
[       OK ] ConfigureRequestBuffer.NoRearmBufferLockOnNoRelease (0 ms)
[----------] 10 tests from ConfigureRequestBuffer (1 ms total)

[----------] Global test environment tear-down
[==========] 10 tests from 1 test case ran. (1 ms total)
[  PASSED  ] 10 tests