libzahl - big integer library

http://git.suckless.org/libzahl/tree/
The rationale for its creation can be found on the README file.
What do you think?

I ran hebimath through PVS-Studio.

hebimath/check/p/pcmp.c 33 err V512 A call of the 'memset' function will lead to overflow of the buffer 'y'.
hebimath/check/p/pnorm.c 30 err V512 A call of the 'memset' function will lead to a buffer overflow.
hebimath/check/p/negnot.c 22 warn V756 The 'i' counter is not used inside a nested loop. Consider inspecting usage of 'n' counter.