Don't crash when no WM is present.

CR: Sam Lantinga.
Fixed large relative mouse motion when iconifying the SDL window.
Windows will move the window to -32000,-32000 when it is iconified, so we don't want to send mouse motion for iconic windows.
Fixed bug 2260 - SDL_SetCursorGrab() is buggy on Windows

BurnSpamAddress

Steps to reproduce:
1. Grab the cursor with SDL_SetCursorGrab()
2. Alt-tab away from the window
3. Click on the titlebar of the window

This will cause the window to disappear underneath the taskbar!

This appears to be a general issue with ClipCursor() on windows, i.e. I am getting the same behavior if I call ClipCursor() directly.

It is caused by a feedback loop between the ClipCursor function and the modal resize/move event loop that handles mouse-based sizing on Windows.
Added alternative XBox 360 controller GUID on Linux

Leszek Godlewski

As described in the other thread
(http://lists.libsdl.org/pipermail/sdl-libsdl.org/2013-November/091997.html),
I've run into a case of SDL2 not recognizing a wireless Xbox 360
controller receiver properly on Debian Linux amd64 testing.
Apparently, the generated GUID is slightly different.

Device in question:
Bus 001 Device 015: ID 045e:0291 Microsoft Corp. Xbox 360 Wireless
Receiver for Windows