gsm improvements

gsm improvements
code cleanup

	modified:   README
	modified:   action.cpp
	modified:   action_efi.cpp
	modified:   action_vbox.cpp
	modified:   alawulaw.c
	modified:   bchannel.c
	modified:   bootstrap.c
	modified:   callerid.c
	modified:   cause.c
	modified:   chan_lcr.c
	modified:   default/gsm.conf
	modified:   dss1.cpp
	modified:   gsm.cpp
	modified:   gsm.h
	modified:   gsm_conf.c
	modified:   message.h