move child_scopes() out of factory method scope::search()

[Kyle Nitzsche]

Factory methods should return as quickly as possible. Currently child_scopes() is called while being passed to the Query constructor inside scope::search() (a factory method). This creates the potential for timeout exceptions.

Therefore, the child_scopes() should be moved, perhaps into the Query::run() method, since that has no time constraints and the Query has a pointer to the Scope and so can run the method.

[Kyle Nitzsche (knitzsche)]

fixed with release 1.5.22