set indent_style to valid value

Per the documentation for editorconfig the two valid values for ```indent_style```  are 'tab' or 'space'
Merge pull request #2980 from eriko/patch-1

set indent_style to valid value
Version bump to v1.2.0.beta2
FIX: Sharing link stood visible after using browser’s back button
update rails
FEATURE: log out user everywhere and refresh/redirect
Update DEVELOPER-ADVANCED.md

To install the gem pg-0.15.1, you need to have libpq-dev installed. Otherwise bundle install will fail.
See http://stackoverflow.com/questions/16788062/error-running-gem-install-pg-v-0-15-1
FIX: TL4 flag on TL0 post as spam, hides the post
Merge pull request #2984 from cpradio/pr-tl4-flag-spam-post-hidden

FIX: TL4 flag on TL0 post as spam, hides the post
FEATURE: show exact error for test email
Merge pull request #2982 from techAPJ/patch-2

FEATURE: show exact error for test email
remove /download from csv file url
Merge pull request #2985 from techAPJ/patch-3

remove /download from csv file url
UX: improved our footer handling

- new "show-footer" mixins
- converted most of the routes to ES6
- FIX: handling of "indexStream" in user pages

There will now be a footer on all the following pages
- /exception
- /about
- /latest
- /new
- /unread
- /starred
- /top
- /categories
- /c/:category
- /c/:category/l/latest
- /c/:category/l/new
- /c/:category/l/unread
- /c/:category/l/top
- /t/:topic/:id
- /groups/:name/members
- /user/activity
- /user/activity/topics
- /user/activity/posts
- /user/activity/replies
- /user/activity/likes-given
- /user/activity/likes-received
- /user/activity/bookmarks
- /user/activity/starred
- /user/badges
- /user/notifications
- /user/flagged-posts
- /user/deleted-posts
- /user/private-messages
- /user/private-messages/mine
- /user/private-messages/unread
- /user/invited
- /user/:username/preferences
- /faq (static pages)
- /badges
- /badges/:id/:badge
UX: improve ip-lookup modal

- replace close button with cross
- use table instead of ul/li
- use trust level number instead of full name
- sort users by descending trust level
- add post count
add allowed_ips to api_keys

update annotations
correct import script
FEATURE: allow restricting API keys to a particular range
add support for hidden api keys, used in hosting scenarios
FIX: don't crash from observer if user record is bad