rlk/envtools — pull request #3 by 1ace (2014-01-08 00:07:02+00:00)
Title: Added lib math to `Makefile`, renamed M_PI to PI and added missing `#define` in `envtoirr.c`

I made a mess of my `git` history, so I decided to make a new commit with only the useful bits; here's the update [as requested](1#issuecomment-31658096).