FIX: shift+click on links

Default browser's behavior when shift+clicking was messed up.

This adds the shift key modifier to the list of click modifiers in both
`click_track` and `discourse`.

Also updated & refactored a bit the `click_track_spec`.
Remove imdb onebox for legal reasons
Align star to the top of the line in topic list for topics showing excerpts
Fix bookmarks admin dashboard counts to include bookmarks that were deleted
increase default max_likes to 50

WE LIKE LIKES MAN
too many pleases
normalize on "private message" vs "conversation"
Merge pull request #796 from ZogStriP/fix-shift-clicks-on-links

FIX: shift+click on links
firefox used to display "loading..." on back sometimes
vagrant detection attempt
added option to force polling instead of messing with the detection
oops
:s/POST/REPLY/g
no_js to use site customisations
correct base url in emoji so I can close bug
simplify pinning message a bit
this is a slightly round about way of making our self oneboxes sane
shrunk avatar to 60px, added global whitelisting