Added release branch for 1.8.x

svn path=/branches/releases/1.8.x/; revision=9558
cherry-pick r9635

svn path=/branches/releases/1.8.x/; revision=9640
Fixed make distcheck.

svn path=/trunk/libavg/; revision=9643
Re-added FX render-on-demand functionality.

svn path=/trunk/libavg/; revision=9644
FX rendering optimization.

svn path=/trunk/libavg/; revision=9645
Cosmetics.

svn path=/trunk/libavg/; revision=9646
Build fix.

svn path=/trunk/libavg/; revision=9647
Fixed setOGLOptions docs.

svn path=/trunk/libavg/; revision=9648
Add fallback to standard glxcontext, if debug glxcontext creation fails

svn path=/trunk/libavg/; revision=9649
Fix XInput error, #489

svn path=/branches/releases/1.8.x/; revision=9651
Windows build fix.

svn path=/trunk/libavg/; revision=9652
1.8.x branch: cherry-pick 9648 from trunk.

svn path=/branches/releases/1.8.x/; revision=9653
1.8.x branch: cherry-pick 9629, 9630 from trunk.

svn path=/branches/releases/1.8.x/; revision=9654
1.8.x branch: cherry-pick 9637, 9636 from trunk.

svn path=/branches/releases/1.8.x/; revision=9655
1.8.x branch: Updated NEWS.

svn path=/branches/releases/1.8.x/; revision=9656
Merged r9651 from release/1.8.x to trunk (fixes #489).

svn path=/trunk/libavg/; revision=9657
A tiny little bit of RAII

svn path=/trunk/libavg/; revision=9658
Enable X11ErrorMsg handling before trying to create fallback GLX-Context

svn path=/trunk/libavg/; revision=9659
Remove obsolete AVG_ERR_DEBUG_CONTEXT_FAILED

svn path=/trunk/libavg/; revision=9660
Correct error message when GLX context can't be created.

svn path=/trunk/libavg/; revision=9661