Bug 772598 - Use "Site settings" instead of "Site preferences" in clear private data dialog.
Bug 669262 - Lightning cannot do semi-monthly entries.
Bug 410427 - Event Dialog: Allow setting recurrence "UNTIL" without custom dialog.
Merge changes from beta
Bug 733822 - Update internal timezone database from version 2011n to version 2013a.
Fix bug 827279 - Show Accept/Decline buttons even for processed messages in imip bar.
Bug 848138 - Tooltips for tasks show Priority item as "Medium" instead of "Normal".
Fix bug 848424 - Show EXDATE and modified occurrences in email invitation template.
Fix bug 489162 - No accept/decline button for invitations with GCal.
Bug 349529 - Investigate in-view task UI of tasks with missing date or due date.
Bug 825452 - When System integration dialog is opened from preferences, use "cancel" for the cancel button.
Bug 263736 - Group by sort feature with sort by "Date" uses "Old Mail" in RSS folders and newsgroup.
bug 588415 - Make website storage mechanisms available in Data Manager (localStorage, indexedDB, etc.)
Bug 807326 - Context menu Search should be available in textareas/inputs as well.
Bug 845353 - New 3rd-party cookie restriction to visited websites is default but not an option in Cookies pref pane.
Bug 842191 Implement notifications for mixed content blocker
Bug 852461 - Remove growl support from comm-central again now that bug 782211 has landed
Bug 283425 - Add prefs UI for option to disable (don't show) the new-message tray icon.
Bug 448624 - Remove imap specific "Empty trash" confirmation dialog and merge mailnews.*.dontAskAgain and mail.*.dontAskAgain prefs.
Fix parse error