Be accommodating to the absence of either nucleotide or protein databases.

All users may not use both nucleotide and protein databases.  If either
category is missing, SequenceServer shows an empty grey box in its place.
Let's change it so that other databases expands to fill in that space.

Closes #62.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Sort databases alphabetically, by their title, regardless of the case.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>