Fix 32-bit typedefs. Fixes Linux 64-bit target issues.

Related to #188 

This fix was prompted by @anhinga's discovery of an issue with the table lookup oscillators in Linux for 64-bit targets. The typedef for 32-bit integer types was not target-agnostic, and was resulting in 64-bit integers on 64-bit targets.

In theory, 64-bit platforms are now supported although I don't think we should officially support 64-bit until we're sure there are no other issues.

@Dewb can you take a look at the fix here and make sure I didn't do something that will break on Windows? I wasn't sure if `<stdint.h>` is valid in MSVC.