begin converting packet serial/deserialization to use strings

previously used stringstreams on the interfaces which made some issues
now that i see we're moving to compression
convert server to use the new packet api
convert client to the new packet api
fix serfver use of &ss
fix use of constness
reinstate packet::serialize which compiles..but hopefully works, too
reinstate deserializepackettype
reinstate deserialize
proof of concept, serialization working

now i just need to find a nice means to separate the header and the
contents, methodically
serializing sort of works and split out packet contents and header

the serialization for each is now separated cleanly, to aid better for
our "should we compress or not" logic.
return a full string with both header and contents in ::serialize
new & improved serialization works now, no compression just yet
add compressed/uncompressed flags to packets
almost implement deserialization for compressed packet contents
set compressed bool on the packet header

presently nothing uses it, however.
prepare serialization for compression
add some debug statements and make it clear that deserialization is broken

specifically, decompressing. and i'm not even compressing yet, just
acting like i am. has to do with the different streams and how i want
just the goods after the header, etc..
compression/decompression should in theory, work. now time to implement it
wow, i'm pretty sure compression is working. the game runs, at least

haven't tested compression rates or validity.
cleanup and doc fixes