Display id instead of accession number in the sequence modal.

This works correctly only on BLAST 2.2.30+. Older BLAST+ will include 'lcl|' in
the id for non nr and blast databases which is unwanted. We could have stripped
'lcl|'. Instead we will change minimum BLAST+ version requirement (because we
anyway need at least 2.2.29+ for sequence retrieval to be robust).

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Refactor, document and clean up Sequence class.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Unit tests against #88

Sequences with only numeric FASTA ids are not properly retrieved using
blastdbcmd. While our hack fixes this, it is to be reported upstream.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Don't show FASTA dld link in Query header if no hits

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>