acc: no request is needed for setting end time on dialog termination

- callback function cdr_on_end() doesn't use it at all
- reported by Eduardo Lejarreta, FS#256

(cherry picked from commit 8fcdd23aaa49cb6c1ecb34c4c6b4a88078a860f7)
(cherry picked from commit 4455a13e8d31416dc44af455710fd7a7ff37ec11)
dialog: copy dlg var value locally on get operation

- reference to shared memory exposes risk on accessing an invalid
  pointer if anothe process updates it
- reported by Dragos Oancea

(cherry picked from commit bb3eed8aabea9f63c9922f71714aea242771db02)
(cherry picked from commit b76eb77a36a5e751d792cb7e0d60f4750976e322)
rtmier: reset avps and xavp lists after route blocks execution

- avoid leaks if someone is using avp/xavp with rtimer - there is a fake
  message used there, thus not the normal sip message routing that
  resets avps/xavps

(cherry picked from commit 159978cf2a98748f3225155d8946bcbd768b51e3)
(cherry picked from commit c5781b28cd92360cf163a84312fa72c08c4737b5)