-remove some compiler warnings showing up in VS2010

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10732 ddefafc4-47db-0310-ae44-fa13212b10f2
-UAS Prack enhancement allow provideOffer to be called immediately after an  
 provideAnswer/reliable-provisional instead of need to wait for the onPrack callback
-added new TFM test case to cover this scenario:  testPrackNegotiatedReliableUASUpdateFast

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10733 ddefafc4-47db-0310-ae44-fa13212b10f2