Fix tags like `short_shorts` or `hunter_x_hunter` being highlighted
incorrectly. Typing `short_sh` would highlight it as SHort_SHorts
instead of as SHORT_SHorts.
Fix usernames not being highlighted when completing @mentions.
This also changes it so the autocomplete results don't include the '@'
in front of the name.
Minor breaking change to the /autocomplete.json API. Autocomplete
results for mentions now have the type `mention` instead of `user`.
Highlight the matching part of the tag in the autocomplete menu. For
example, if you search "hair", then the word "hair" will be bolded in
every matching tag. This is so users can tell why a particular tag was
matched.
Render the HTML for autocomplete results server-side instead of in
Javascript. This is cleaner than building HTML in Javascript, but it may
hurt caching because the HTTP responses are larger.
Fixes#4698: user autocomplete contains links to /posts
Also fixes a bug where tag counts in the autocomplete menu were different
from tag counts displayed elsewhere because of differences in rounding.
