Added support for service that returns a list of registered services.  See this ancient issue for details:

http://sourceforge.net/tracker/index.php?func=detail&aid=1174796&group_id=100909&atid=628622
Merged changes from trickplay's fork.
Initial crack at some documentation, at the moment mcastsocket is the only thing that has usage docs
Fix up the built documentation a bit
Note how to build the docs
Note how to run and test...
Make the instructions a bit more coherent
Imports rearranged and standardized along the different sample scripts.
Setting TXT record with two Key/Value Pairs.
TXT record directly set on ServiceInfo's constructor.
Stringify DNSAddress more better