* [Calendars/Watchers] When a worker adds a new event or recurring event to a calendar, a notification will be sent to any watchers of that calendar.  This makes it really easy for a worker to notice when someone adds an event to their calendar for them.
[Parser/Code Cleanup] Fixed an issue in the parser where messages from senders that were workers are always set to 'worker_id=1' due to using a boolean rather than an ID.
[Code Cleanup] Removed a function in cerberus.js that's no longer used anywhere.
[Dates/Usability] $.cerbDateInputHelper() can accept an options object as its only argument. The only option at the moment is a 'submit' callback, which allows the caller to respond to the 'Ctrl+Shift+ENTER' keyboard shortcut.  For instance, this allows dates to be resolved, and then a parent form submitted in the same keystroke.
* [Mail/Reply/Keyboard] When replying to a ticket, the Ctrl+Shift+Enter keyboard shortcut will instantly send the message.
* [Mail/Reply/Keyboard] When replying to a ticket, three new shortcuts will automatically set the status of the ticket.  Ctrl+Shift+O (open), Ctrl+Shift+W (waiting), Ctrl+Shift+C (closed).  This saves extra mouse clicks, or the use of TAB to navigate down the page.
* [Mail/Reply/Dates/Keyboard] When replying to a message and entering a 'wait until' date, the Ctrl+Shift+Enter shortcut will convert the date and then send the message in a single keystroke.
[Code Cleanup]
* [Workspaces/Export] Workspace pages and tabs support the ability to export their configuration to a plaintext format (JSON). This option may be accessed from the page menu (gear icon) in the top right.

* [Workspaces/Import] Workspace pages and tabs may be imported (in the same JSON format they export to).  This provides a simple way to clone or share useful workspace configurations, either within a Cerb environment or externally. Pages can be imported from the create page popup; tabs can be imported on a specific workspace page from its '+' tab.

* [Workspaces/Usability] Workspace pages now display a configuration menu in the top right instead of a toolbar.  This provides space for more options without adding visual clutter. The tab-related options (e.g. Edit Tab) are now hidden when the currently selected tab doesn't support those options (e.g. the built-in '+' tab).

[Workspaces/Code Cleanup] Moved workspace pages and worklist tabs into extensions. Previously the code handled a bunch of empty($extension_id) exceptions for these as defaults.
6.4-early-release checkpoint