158968 - command line option for kiosk mode

User Story

As a system administrator I want to launch Firefox in kiosk mode, so that Kiosk users can navigate through web pages without Chrome or OS access. The kiosk mode prevents user interaction and activities on the device outside the scope of execution of the browser

Acceptance criteria:
- OS support covers Win7+
- When launched in Kiosk mode, Firefox Runs only in full screen
- All menus, awesome bar and toolbar are not visible as well as tabs. 
---- No X button when you hover to the top of the screen can be seen
---- F11 does not work. 
---- Removes the status bar in the bottom left for progress or for hovering over links.
---- Links that would open a new tab will open in a new tab, but that tab is not navigable directly via the user interface.
- Prevent right click context menu

Numerous features of the kiosk mode are already configurable through policy or command line parameters when launching the browser. We assume that system administrators will be using Firefox as follows:
- Configure accessible domains through policy
- About: pages are disabled through policy
- Launch Firefox through command line with “-private-window URL” parameter so that Firefox is launched in a private Window (Clear the cache, user history and form data between sessions) and pointing to a pre-defined URL
- The homepage is set through policy