[FIX] Adapted the ucsc format to the new stream interface.
[FIX] Adjusted the bed-io to the new stream interface.
[FIX, FEATURE] Adapted the gff parser to the new stream module.
Merge branch 'vcf_io' into ucsc_io
[FIX] Complete the ucsc test.
Merge branch 'ucsc_io' into bed_io