Delegate :username rather than using a class method.

This is just a little cleaner?
Trust level 3 users can edit topic titles and change category
Sanitize your bio after you save it and render it to yourself.
Version bump to v0.9.8.2
Topics Entered -> Topics Visited
whoops, I meant "Topics Viewed"
minor /top copyedit
another minor /top copyedit
BUGFIX: do not install dependencies from plugin, must be explicit
FEATURE: script/discourse import AND export
BUGFIX: export was broken, not exporting any tables
BUGFIX: support nil params
fix for nil session in mobile_detection.rb
DIEEEE SOFTWARE.MD DIEEEEeeEE
FIXES #1833, thanks @stefanpenner
Trust Level 3: invited users start at default_invitee_trust_level + 1, unless default_invitee_trust_level is 2 or higher
In development mode, if an avatar is missing just serve up a placeholder
Renames `unboundDate` to `rawDate` because `date` is current unbound.
FIX: Incorrect comment, thanks @ZogStrIP
rename `date` to `unboundDate` because it is unbound.