Revert "C++ compatibility"

This reverts commit 1020d3cda4e93ee04e90b77a51ed71382b83f80d.

Conflicts:
	lib/libimagequant.c
	lib/nearest.c
	lib/pam.c
Revert "Casts for C++"

This reverts commit 28631189b11b8e941f3b06b31f3a70ce252263b7.
Revert "C++ fixes"

This reverts commit 8d374732710c7193529fbd93fa0fec2835b741de.