Task/499 network part of issue

### Description
o Fixed the 'network part' of issue #499 (part 1 of uncached queries/updates for context providers).

o About adding CB_PORT as preferred variable to BROKER_PORT, doing the FULL change, i.e. completely stop using BROKER_PORT etc is a too big task to include in this PR. I tried but it got BIG. Coming in a PR soon.

o About statistics, I have passed completely on the statistics in this PR. There are two new messages 'QueryContextResponse' and 'UpdateContextResponse' but they are NOT included in the statistics. Perhaps this was not a good idea, and it is easy enough to include them. However, I have a feeling the entire statistics concept needs to be looked over ...

o I had some problems with the compiler copying entire vectors, in the clone/fill functions. I changed a few of them from 'const Class&' to 'Class*'. Also, I changed the name 'clone' to 'fill' for the methods that don't actually clone anything (methods that just fill).

This is the errorCode of the response to the client?

In this case, I'd suggest to use 404 Not found. Take into account, that all the process about redirection, fowarding query/update, etc. is "opaque" to the client. If the broker fails in resolving the redirection (no matter the cause) the client shold recieve a 404 Not found.

However, I fully agree with loging a warning due to bad input in the CB log file (as you already do).