XEP-0065,XEP-0096,XEP-0166,XEP-0235,XEP-0300: file transfer improvments:

huge patch sorry :)

many things are improved by this patch, notably:
- updated to last protocol changes (urn:xmpp:jingle:apps:file-transfer:5 and urn:xmpp:hashes:2)
- XEP-0234: file request implementation
- XEP-0234: methods to parse and generate <file> element (can be used by other plugins easily)
- XEP-0234: range data is now in a namedtuple
- path and namespace can be specified when sending/requesting a file (not standard, but needed for file sharing)
- better error/termination handling
- trigger points to handle file requests by other plugins
- preparation to use file plugins with components

src/plugins/plugin_xep_0096.py

@@ -244,7 +244,7 @@ class XEP_0096(object):
         client = self.host.getClient(profile)
         return self.sendFile(client, jid.JID(peer_jid_s), filepath, name or None, desc or None)
 
-    def sendFile(self, client, peer_jid, filepath, name=None, desc=None):
+    def sendFile(self, client, peer_jid, filepath, name=None, desc=None, extra=None):
         """Send a file using XEP-0096
 
         @param peer_jid(jid.JID): recipient
@@ -252,7 +252,7 @@ class XEP_0096(object):
         @param name(unicode): name of the file to send
             name must not contain "/" characters
         @param desc: description of the file
-        @param profile: %(doc_profile)s
+        @param extra: not used here
         @return: an unique id to identify the transfer
         """
         feature_elt = self.host.plugins["XEP-0020"].proposeFeatures({'stream-method': self.managed_stream_m}, namespace=None)