GFX now handles non-default adapters

The GFX (DirectX) pipeline did not respect the choice of adapter and
always went for the default one.  Normally this isn't an issue unless
you wish to target a particular adapter and display device combination.
This has been corrected.

The GFX initialize functions now attempt to find the best adapter that
matches a given display device (i.e. monitor) if one has been passed in.
To aid with choosing a display device some new monitor enumeration
methods have been added to the platform window manager.  These methods
have been exposed to the Canvas.

Engine/source/windowManager/platformWindowMgr.h

@@ -71,6 +71,25 @@ public:
    /// @return The current desktop bit depth, or Point2I(-1,-1) if an error occurred
    virtual Point2I getDesktopResolution() = 0;
 
+   // Build out the monitor list.
+   virtual void buildMonitorsList() {}
+
+   // Find the first monitor index that matches the given name.  The actual match
+   // algorithm depends on the implementation.  Provides a default value of -1 to
+   // indicate no match.
+   virtual S32 findFirstMatchingMonitor(const char* name) { return -1; }
+
+   // Retrieve the number of monitors.  Provides a default count of 0 for systems that
+   // don't provide information on connected monitors.
+   virtual U32 getMonitorCount() { return 0; }
+
+   // Get the name of the requested monitor.  Provides a default of "" for platorms
+   // that do not provide information on connected monitors.
+   virtual const char* getMonitorName(U32 index) { return ""; }
+
+   // Get the requested monitor's rectangular region.
+   virtual RectI getMonitorRect(U32 index) { return RectI(0, 0, 0, 0); }
+
    /// Populate a vector with all monitors and their extents in window space.
    virtual void getMonitorRegions(Vector<RectI> &regions) = 0;