Hedera 0.2

   * Added the address book listener, so we can handle updates.
   * Split out the code to push a single card to Couch - so we can re-use
     it from the address book listener.
   * Re-named the Hedera Contact class so it's less likely to clash.
   * Moved the code to translate a nsIAbCard to a Couch contact into a
     static method on the Hedera class so we can use it from the address
     book listener.
   * More logging in HederaContact.setProperty().
   * Kill the unnecessary (old, Thunderbird 2) RDF Service.
   * Use the Address Book Manager to get the directories instead.
   * Replace 9 lines of boilerplate to get the Address Book Database
     using old (Thunderbird 2) code with 2 lines of new (Thunderbird 3)
     code.
   * Improve Hedera.writeError().
   * Use Hedera.writeMessage() to write debug messages in HederaContact.
   * Correctly retrieve the revision on stored contacts.
   * Wrap the Observer.onItemAdded() logic in an exception handler.
   * Added an addrdb to the MergeableList.append() parameters to allow
     us to correctly query and set card properties.
   * Modified the various get* methods in sync.js to pass the new
     addrdb.
   * Pushing contacts on creation now works!