Merged support for non-BoundingRegionShelve-tracks
Reverted incorrect change
Added support for ##FASTA (ignoring the sequences)
Added GffCategoryGenomeElementSource. Made FastaGenomeElementSource a sliceSource for improved performance. Updated tests.
Merge http://github.com/sveinugu/gtrackcore

Conflicts:
	gtrackcore_memmap/input/adapters/TrackGenomeElementSource.py
	gtrackcore_memmap/input/core/GenomeElementSource.py
	gtrackcore_memmap/input/fileformats/FastaGenomeElementSource.py
	gtrackcore_memmap/test/input/core/TestGenomeElementSource.py