win32: Core project compiles with VS 2012 and gcc-4.7.3

Signed-off-by: Benn Snyder <benn.snyder@gmail.com>
win32: Fix 1 error and 2 warnings

Signed-off-by: Benn Snyder <benn.snyder@gmail.com>
Merge pull request #383 from OpenKinect/win32

win32: Core project compiles with VS 2012 and gcc-4.7.3