Added Jabsorb-RPC provider to iPOPO

Compatible with the Java implementation of remote services available at
https://github.com/isandlaTech/cohorte-remote-services

using the fork of the Jabsorb library, available at
https://github.com/isandlaTech/cohorte-org.jabsorb.ng
Added new packages to setup.py

- pelix.misc (containing Jabsorb translation methods)
- pelix.remote.transport (that will contain future RPC implementations)
Updated the module description
Jabsorb-RPC: use contant component factory names
Added a mDNS service discovery provider

- Based on pyzeroconf (works in Python 2 only :( )
- Support service addition and removal (no service update)
- Compatible with ECF (if pyzeroconf is patched)