update fog gem to latest
removed old rake task until it's updated
enable thumbnailing on S3

- added url to optimized image model
- refactored s3_store & local_store
Update INSTALL-ubuntu.md

The removed paragraph was useful for a previous version of the "Updating Discourse" code above it. It seems useless now, as precise instructions are already in the code comments. In fact, it became incoherent, as we explicitily have "bluepill quit" in the code now.
odd formatting
working plugin interface for custom openid auth, custom css and custom js
pretty text would blow up on an <a tag with no href
plugins should not be checked in
auto generated files should not be checked in
when there are no providers do not blow up
ensure directory at the correct spot
support server side js and arbitrary assets
proper chaining for emoji so other hooks can be called
Merge pull request #1276 from jbruni/patch-1

Update INSTALL-ubuntu.md
Merge pull request #1275 from ZogStriP/enable-thumbnailing-on-s3

Enable thumbnailing on s3
Change category by editing first post updates topic title
Rename the PK index to support table rename
Upgrade jQuery to 2.0.3
FIX: Post Menu wasn't updating the bookmark icon properly.
add foreground color to @mentions