API: Removed Maven dependency to OSGi core
Corrected call to peer_registered() when binding a directory listener

The binding method was still calling the old name "peer_added"
Added Peer.dump() and added behavior to Peer.set*()

Java version of Peer now behaves like Python one
Corrected internal interfaces definitions
Added a RawAccess implementation of Access

- Will be used to store raw data awaiting for a transport directory to
parse it
- Removed the equals() and hashCode() methods from Access
Added new services interfaces and constants

- IConstants: properties constants, as defined in herald.core
- Added Listeners interfaces
Added a utility package for Herald

- Event: same as Python's threading.Event()
- LoopTImer: same as the one in herald.core
Added the Java implementation of Pelix's EventData
Removed test folders from Eclipse project classpath
Corrected wrong validity check: callback instead of errback
Corrected usage of Directory._names in Python (beans vs. UIDs)