+ print warning if we cannot increase buffers to specified value

* seems to work smoothly with recent GPUJPEG library

* currently 9.0 is needed

* make the library compile again (not only with UltraGrid)
* small changes (mainly dependecies and cleanups)

TODO: figure out deleting SAGE objects (reconfiguration + exit), since
it seems that this piece of SAGE is not working correctly

TODO: validate and possibly rewrite all the getf/putf staff

Conflicts:
	ultragrid/configure.ac

* to get rid of annoying complains to its absence
* TODO 1: find out how to release AP without SEGV (disabled now)
* TODO 2: recheck if there are no other memory leaks with Mac