Blender Git Loki

Fix compilation error after recent libmv change

- Tweaked typedefs in stdint so they match
what we've got in BLI_sys_types (needed to
explicitly tell sign to MSVC).

Not so much harmful to be more explicit here,
but we really better to have single stdint
int blender.

- Tweaked allocations macros so MSVC is happy
with structures allocation.