UC-116 Add a FB client service + isolate fb map exception
UC-116 Add new i18n messages
UC-116 Use the FB client service and needed refactoring
Add User signup to the excluded-return-to pages
UC-116 Rename setAjaxyErrorResponse -> setErrorResponse
Replace User Id with username
Remove Exceptions/FacebookMapModelException.php + fix typo
Rename FacebookClientService to FacebookClientFactory per @garthwebb
Add todo messages for js fix of UC-187
FB Client Factory method returns Status
User should not be allowed to create a Wikia account with ...
... a facebook account that is already connected to an existing Wikia account
Properly handle message parameters
Address feedback from @lizlux
Merge branch 'uconn-3' into UC-116
Merge pull request #5804 from Wikia/UC-116

UC-116 Facebook Client Service & improved user-mapping related error handling