Add forgotten $overlay pass-through in MWReferenceDialog

We were doing this for the exact same widget in
MWReferenceListDialog, but not here.

Change-Id: I4a905b944be44ec1aec5cdba7580283ec18c5c7c
(cherry picked from commit 884aa1f2430b915c62c3682cbb85667233a87bd2)
MWTransclusionDialog: Blur active input when switching modes

When show/hide options is clicked, the inputs in the main pane
move as the outline transitions in or out. This causes any dropdowns
below these inputs to become mispositioned: they don't move
because they're in an overlay.

To work around this problem, blur the active input when show/hide
options is clicked, so any dropdown attached to it is closed.
I tried blurring and immediately refocusing the active input to
force the dropdown to reposition itself, but that looks awkward
because of the transition (we'd have to wait for the transition
to complete before repositioning it, and during the transition
it'll stay open in the wrong place).

Change-Id: Ibd963690573af905066839f7276077089fa893c6
(cherry picked from commit c324ed8b9a438b2c19de2ec2b894ed18f729689a)
Merge "MWTransclusionDialog: Blur active input when switching modes" into wmf/1.25wmf6