Visual Studio 2010 support

-Re: #597 
-Tested on 32-bit Windows 7 and 64-bit Windows Vista with VS2010 Express with SP1
-NOTE: the script tries to fetch Qt from a broken URL and this is not fixed on purpose as it's already fixed in the mainline https://github.com/realXtend/naali/blob/tundra2/tools/windows-build-deps.cmd#L166
-Bullet build improved by using CMake and by omitting the unnecessary samples and demos from the build

Known issues:
-<b>Speex is skipped for now</b>, the solution and project files need hacking in order to make it build with VS2010
-Even though Celt seems to build fine, MumblePlugin fails to link to it
-VLC's VS2008-built binaries are not compatible with VS2010 binaries, so VLC is skipped in the process