rename various magic names.

rename various magic names.
	sigi and sigt:
	sys·sigi_inter -> sigi·inter
	sys·sigt_int -> sigt·int
	Package·sigt_Type -> sigt·Package.Type

	local type T in file x.go T_x -> T·x
	second one T_x_1 -> T·x·1

	method names M on T  T_M -> T·M

correctly handle local embedded types

init functions are the only place left that use underscores

R=ken
OCL=18377
CL=18377