utils proto: Added utility functions for protocol handling.

So far, added functions to send data to an open file descriptor and use that
in the frontend code.
utils proto: Added sdb_proto_get_int().

This function “recieves” a 32bit integer from a string buffer and converts it
from network to host byte order.
Added initial client library implementation.

For now, this includes a network client only.
Link proto and strbuf utilities into libsysdbclient.
Added version functions to libsysdbclient.

This is basically the same as the sdb_version() functions but to be used only
in the client lib.
util strbuf: Let skip() support an offset.

That is, add support for removing bytes from the middle of the buffer.
strbuf_test: Added skip() tests using various offsets.
client: Let client_recv() not pass unparsed status,len to the caller.
client: Let client_recv() read a full response.

… and block if necessary. There is no reason that a client should handle
partial responses.
sysdb: Added a initial client implementation.

For now, this is basically a placeholder.
sysdbd: Fixed a typo.
sysdbd: Changed -d option to -D and default to daemonizing the process.

It doesn't really matter much what the default is but -d should be reserved
for debugging.
Updated various copyright notices to 2012-2013.