Allow PySide to build for embedded environment.

I have been using PySide in an embedded environment (QWS/LinuxFB) for some time now, and it works fantastic. However, to get it built to do so is a real pain that involves many tweaks to both the XML files and the CMake files, mostly disabling stuff that doesn't apply to an embedded environment, or stuff that I am not planning on using that just causes build errors. I am not familiar enough with all of the internals to fix this properly, but I can make it work good enough for my use. It would be great to have this officially supported.
I can provide patches if required, to help, but they are mostly hacks.