Update read cleaning code.

Only considers read 1, now matches exactly the known sequences
(the two adapter sequences and the restriction site sequence).

Between the left and right adapter sequences is the enhancer sequence.
16 bases to the left of the restriction site sequence is the barcode
sequence.
Fixed enhancer sequence file.

This has the correct left and right adapter sequences.
Fixed version.
Remove crufty version of bam_to_table.
Merge branch 'master' of https://github.com/hbc/gray-enhancers

Conflicts:
	code/bam_to_table.py