Ensure the Scanner/InputStream is closed after getUrlPostResult()
Client container instantiates correctly

- ID is computed by a single method, to have the same endpoint ID on
both host and consumer sides.
- JabsorbContainer let its parent create the RemoteServiceRegistration
bean by calling registerCallables, with all public methods of all
interfaces/classes implemented by the remote service and accessible at
the time of the import.
JabsorbClientService uses the accesses service property

... instead of the URI one

Currently selects the first URI in the array, while it should select it
according to the real exporter address.
Added the HTTPSessionProvider for Jabsorb

Required for Jabsorb to work.
Removed unused URI property from constants