make compile with gcc 4.* without warnings. (hopefully with all versions)

make compile with gcc 4.* without warnings. (hopefully with all versions)

	modified:   Makefile
	modified:   bchannel.c
	modified:   chan_lcr.h
	modified:   extension.c
	modified:   gentones.c
	modified:   genwave.c
	modified:   joinpbx.cpp
	modified:   tones.c