Rudimentary framework for External Link Customisation

Add working link generator methods (tested on nr) for Sequence viewing,
FASTA Download, and NCBI. In order to provide more flexible url
customisation, we provide whole Database objects to the link
generating methods.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Merge remote-tracking branch 'vivek/master' into next

* vivek/master:
  Rudimentary framework for External Link Customisation

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Extra line number was shown in modal due to line endings. Fix that.

Also, made the citation consistent with the rest of the places.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Escape sequence ids in sequence retrieval links.

Additionally, introduce ability to order the links and add custom CSS classes.

[ap: commit message]

close #112

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Add some databases for testing.

Includes
- database containing sequences with weird ids
- database created without using parse_seqids option

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Use hit accession no. instead of id

Accession number can also be used in place of hit ids for querying using
blastdbcmd. With this change, we can prepend 'lcl|' to accession no. and
not only can obtain hits as before, but also treat special cases like
issue #88.

Should close #88.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Fix FASTA download via Modal.

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