Generally moves all the plugin code into xcomposite-input.cpp and
removes all C++ dependencies.
Migrate as much as possible to xcb from Xlib to enable us to handle
errors and attribute them to the correct callers. This caused many other
knock on issues such as wrongly attributed errors and cleanup code
working incorrectly.
That allows us to use the xcursor-xcb implementation and delete the pure
Xlib implementation. We also add the missing functionality from the Xlib
implementation to the xcb implementation.
Capture glXCreatePixmap errors which occur most commonly on
nvidia+gnome due to nvidia's driver being unable to allocate more than 1
pixmap per window and gnome being the only compositor to read window
data via glx pixmaps.
Fix cleanup after failed glXCreatePixmap that might have leaked pixmaps
and prevented later captures on nvidia drivers for the same reason.
1604400e48