a) implement a new candidate selection procedure, based on target naming

a) implement a new candidate selection procedure, based on target naming
   context checking and multiple match resolution via an internal search
b) move the candidate listing in a persistent per-thread buffer
c) fix bind procedure
d) minor cleanup

(a) and (b) should address ITS#2935; (b) and (c) should address ITS#3171

A test is also added