Adding removeEdits method to DataStore interface.

This method is used when a rollback from the shadow document is
preformed to clear the edit stack.
Removing ignored and invalid test.
Changes needed for supporting an array of edits.

- The client side needs reworking but this will allow the test to
  succeed. This will be revisited shortly to fully support the diffsync
  client "spec".
Javadoc clean up.
Moving EditBuilder into DefaultEdit class.
Deleted none needed removal of edits as all have been removed.
Update the Client to behave like the server flow.

Need to still deal with edits and packet loss

basic reference app added