src/graphics/OGLImagingContext.h: added include guard
src/graphics/OGLImagingContext.h: added include guard

svn path=/trunk/libavg/; revision=3296

hoodie/libavg,th3infinity/libavg,hoodie/libavg,libavg/libavg,yyd01245/libavg,scotty007/libavg,yyd01245/libavg,libavg/libavg,scotty007/libavg,th3infinity/libavg,th3infinity/libavg,scotty007/libavg,hoodie/libavg,libavg/libavg,hoodie/libavg,th3infinity/libavg,libavg/libavg,yyd01245/libavg,scotty007/libavg,yyd01245/libavg