Improve autocompletion algorithm
Improve autocompletion algorithm

Put stations matching by their three-letter code first, no matter what.  Set
score according to the offset the search substring occurs in each match, so
that mismatches always appear last.

Note that MySQL's INSTR() function doesn't take collation into account.

lcorbasson/rer-web,lcorbasson/rer-web,lcorbasson/rer-web,lcorbasson/rer-web