Adds a checkbox to the page settings pane of the meta dialog that lets
users set or unset the __NOEDITSECTION__ flag on the page.
Change-Id: If1eca58e28d214021f5f5582856e595d4d0fbc43
This creates a new panel in the meta dialog, "Page settings", where page-
level settings will be, err, set. For now, this exposes just the
behavioural switches for the presence/absence of the Table Of Contents –
__NOTOC__ and __FORCETOC__.
As part of this change, the meta dialog is renamed to "Options" to be
less confusing, and the icon for the meta dialog is changed to the
generic one for dialogs, which was previously unused. The page settings
pane is provided first in this list, given that the categories pane
(amongst others) is now directly accessible through the toolbar menu.
Bug: 56866
Bug: 56867
Change-Id: I33ce05c19d2e19b249e1cefd26fd0e3697d0085d