Update docs. Correct errors reported by setup.py build_docs. Add rest interface and link to rest doc to features page. Add link to xmlrpc doc to features page. Add rest doc to index. Update rest doc, hopefully clarify confusing use of parameters in patch action section. Fix code examples in "Adding new rest endpoints" section. Fix example adding import of exception.

try:
    # Python 3+
    from http import client, server
    server.DEFAULT_ERROR_MESSAGE
except:
    # Python 2.5-2.7
    import httplib as client
    import BaseHTTPServer as server