Move version information from api.h

[AndrewLuGit]

Problem:

Currently, building the kernel requires recompiling every file that includes kapi.h, because the version information (PROS_VERSION_MAJOR, PROS_VERSION_MINOR, PROS_VERSION_PATCH, PROS_VERSION_STRING) is updated in api.h whenever the kernel is built. However, the version information is only ever used in the serial daemon, so the vast majority of the recompilation is not actually necessary.

Proposal:

I propose moving the version information from api.h to a separate header file (maybe pros/version.h), so that all of the files that don't use the version information do not need to be recompiled every time the kernel is built.