Dropped solid2fastq.pl

SOLiD is not supported any more.
r297: reduce wasteful SW extension

This is particularly important for long sequences
Test each seed to see if extension is needed

The old version wastefully extends many seeds contained in an aligned region
found before. While this wastes little time for short reads, it becomes a
serious defect for long query sequences.

This is an attempt to fix this problem, but more tuning are needed.
r299: better way to exclude seed