Added two new arguments to epan_init() and proto_init() to

Added two new arguments to epan_init() and proto_init() to
allow the passing of register_all_protocols() and
register_all_protocol_handoffs() through epan_init() to proto_init().
This allows the removal of the compile time dependence of proto.c
on register.h.  Modified dftest.c, tethereal.c, and gtk/main.c to
use the new style epan_init() and depend on register.h.

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@3237 f5534014-38df-0310-8fa8-9805f1628bb7