Last commits were focusing on getting SMS-MT working through http api with multi-level DLR callbacking, many impacts and some fonctional regressions occured in other modules, so this commit has fixed almost* all of these, the unittest compiles with no problems*

(*): The modification of endOutboundTransaction in smpp.twisted.protocol consisting of handling errors in response of a SubmitSm as a normal callback has impacts on the LongSubmitSm, the following tests are no more valid:
 - jasmin.protocols.smpp.test.test_smpp_client.LongSubmitSmErrorOnSubmitSmTestCase
 - jasmin.protocols.smpp.test.test_smpp_client.SubmitSmIncorrectlyBoundTestCase.test_submit_sm_receiver_failure
It'll be done on next commits