Update project to use MSVC 2013 tools

Let's just do it already.

Retaining XP support, using SDK 7.1a (v120_xp.)  Disables SSE2 flag on x64 since it's implied and causes compile warnings.

Differs from #4589 in that XP support is not dropped.  Fixes #4994, fixes #4589, fixes #464 (compiler bug, there may be others it fixes.)

Requires native to be updated at the same time - hrydgard/native#194.

-[Unknown]