[Devel] loop detection fix

[Juha Heinanen]

Bogdan-Andrei Iancu writes:
 > 
 > 1) it;s much much faster - if  I need to encode all into an ID, I need 
 > to parse all the elements which prove a bit expensive...not to count the 
 > encoding; if I do sequential checking with all elements, I can stop at 
 > the first difference (ex; check first the callid - if match, continue 
 > with from tag, etc).

so when initial request comes in, openser checks if it has existing
transaction with the same method, callid and request uri?

-- juha