Added a link to the configuring SSO thread.

Lots of folks who want SSO might not realize it's supported by Discourse out-of-the-box, so I linked to the appropriate thread on the meta forum.
Merge pull request #2499 from toolness/patch-4

Added a link to the configuring SSO thread.
very minor copy update
add Discourse site link to version emails
Alias /guidelines to /faq
Merge pull request #2500 from riking/guidelies

Alias /guidelines to /faq
Import optimizations for topic creation: Prevent queuing of most jobs when importing posts and topics. Only do some recalculations at the end of the import.
BUGFIX: calling .blur() on the body element unfocus the browser window in IE10
FIX: Change the approach to sanitization. Includes a more detailed API
for allowing classes and attributes for only certain tag names.
BUG: mobile user profile field names invisible
BUG: mobile category drop-down styles looked bad
BUG: mobile category drop-down had extra space
very minor copyedit
update launcher command help
PERF: editor could be crashed if you entered huge inline blocks
truncating loooooooooong name fields
Merge pull request #2502 from awesomerobot/master

truncating loooooooooong name fields
fixing d-dropdown heading overlap
Pretty sure anons can't open the composer
FIX: less crazy error when post exceeds max length.