windows compile support. for mvlib
Namespaced MVReturnCode enum values with "MV_" prefix
Applied 'MV_' namespacing prefix changes to MVReturnCode to test program.
Rearranged variable declaration order for msvc in order to compile.
Added support for compiling on windows with msvc
Merge branch 'windows_compile_support'

This was done due to MS' old C89 support.  Simple things like:
- Variable declarations must be at the start of the function
- Windows namespace issues with math.h
- etc.
- etc.