Add Abilitity to 'Dock' HtmlDialogs

[DanRathbun]

Just noting this was requested in a “wishlist” thread recently …

@maxB

SU: add API methods for manipulating the behavior of the trays (checks if open/closed / open / close / flyout-time / autoclose). Also; the current keyboard toggle is not a toggle if a tray is docked to the side. It doesn’t do anything.