Add Ubuntu installation guide
Tweaks to installation documentation
Further modifications to installation instructions
Updated Italian translation
update heroku instructions
update active model serializers to latest
install notes: pull down latest release
Trigger UserActionObserver when updating TopicUser
Trigger UserActionObserver when tracking visit
Merge pull request #875 from Supermathie/sysadmin-docs

Add install notes for Ubuntu
remove moderator status posts from best feed
improve best filter so it properly excludes all admin messages from count as well
Updated zh locales
some helper files for vim
Merge pull request #876 from chrishunt/chrishunt/observe-changes-for-topic-users

Trigger UserActionObserver when updating TopicUser
Merge pull request #878 from emberjs-cn/update-zh-locales

Updated zh locales
Merge pull request #872 from joebew42/client_it

Updated Italian translation
Merge pull request #874 from realdoug/master

Update Heroku deployment instructions
refactor guardian class for clarity & correctness

introduce NullUser to avoid type-checking
DRY up code
reduce number of multiple returns
remove some redundant/impossible logic branches
add pending test for possible bug
add test & fix for ability to flag archived posts
add #secure_category? method to topic class
Fix bug that prevented flagging of archived topics
Rename NullUser to AnonymousUser
DRY up can_<action>? methods
Fix some ownership logic, and a test, for Guardian
Merge pull request #879 from mattvanhorn/refactor_guardian

refactor guardian class for clarity & correctness