Added STR_NOALIGN flags to clistr and srvstr fns. Yes, NT actually does

Added STR_NOALIGN flags to clistr and srvstr fns. Yes, NT actually does
send unaligned unicode strings sometimes!
Fixed our handling of the workgroup name tacked on the end of the
NT1 negprot response (a unaligned unicode)
fixed a couple of places where we should be using the message_end fns instead
of pre-calculated buffer lengths
(This used to be commit 86613493a9b2e56523153486931d0bf8d39beb7a)