Update VE core submodule to master (f2277ea)

New changes:
56de6f5 Localisation updates from https://translatewiki.net.
f8bda64 Widgetise demo menu
6ac48d8 Localisation updates from https://translatewiki.net.
365e131 builderloader: Omit value for boolean "disabled" attribute per HTML5
706e4b3 Prevent double counting of DM nodes in getNodeAndOffset
b141a7d Update OOjs UI to v0.1.0-pre (d2451ac748)
c5b3921 Localisation updates from https://translatewiki.net.
1606983 Update reference to ConfirmationDialog to use MessageDialog

Deletions:
* Styles for ve.ui.MWBetaWelcomeDialog - not needed anymore because
  OO.ui.MessageDialog provides them
* Styles for ve.ui.MWGalleryInspector - not needed anymore because
  ve.ui.MWExtensionInspector provides part of them and the rest are being
  replaced by programatic sizing

Modifications:
* ve.ui.MWLinkTargetInputWidget - Added support for validation and href
  getter
* Split message between tool and dialog title for ve.ui.MWEditModeTool
  and ve.ui.MWWikitextSwitchConfirmDialog

General changes:
* Updated inheritance.
* Added manager param to constructors of dialogs and inspectors.
* Updated use of show/hide with toggle.
* Added meaningful descriptions of dialog and inspector classes.
* Configured dialog and inspector sizes statically.
* Configured dialog action buttons statically.
* Interfaced with OO.ui.ActionSet to control action buttons.
* Moved applyChanges code into getActionProcess methods.
* Always using .next in setup/ready process getters and .first in
  hold/teardown process getters.

Change-Id: Ia74732e6e32c0808eee021f0a26225b9e6c3f971