Minor typo fix in INSTALL-ubuntu.md.
Merge pull request #1641 from toolness/patch-1

Minor typo fix in INSTALL-ubuntu.md.
Refactor Users#upload_avatar method

Moved avatar file upload to ```AvatarUploadService``` class and
```AvatarUploadPolicy```

Address review comments + require missing file in spec
Merge pull request #1637 from railsaholic/refactor_users_upload_avatar_action

Refactor Users#upload_avatar method
Change admin display-row css so that multiple lines can fit in the control column. Don't hard-code a height on the rows.
Some topic list re-organization.
Refactor UsersController#invited

* Add test coverage
* Simplify controller action
* Move finder code to Invite class