Change-Id: Ib3b26ee27f04b2dcbbd32b3127afb45e9f50cfcf

The files are empty and unused.

Change-Id: Ieb4242d14273efdf24149bda33f9591540bba06a

The arm assembly files are named .s after conversion, to reuse
as much of the existing makefile infrastructure for conversion to
gas format as possible. Within the generated visual studio project,
only the converted assembly sources are available, which might not
be optimal for actually developing it, but is acceptable for
just building the library.

Multithreading is disabled since the traditional win32 threading
functions aren't available on WinRT/Windows Phone 8.

Building of vpx itself and the examples succeed, while building the
tests fail due to them using functions not available in the
windows store/windows phone API subsets - therefore the unit tests
are disabled.

This works for building in Visual Studio Express 2012 for Windows
Phone, while Visual Studio Express 2012 for Windows 8 (for
"Windows Store" apps) seems to reject the vcxproj files due to
not supporting "classic style native application or managed
projects". The built static library should be compatible ...