Filled in the guts for pack/unpack

Created all the pack/unpack routines needed. Modified message.h to make
structs uniform and consistent. Client is mostly filled in need to do
"get" routines.
Comment changes
Merge branch 'master' of https://github.com/mdhim/mdhim-tng

Conflicts:
	src/client.c
	src/messages.c
	src/messages.h