Contribution commit from Chris Drake for issue 1103 : Add monitor data for naming/modify conflicts
This makes available 3 new counters in the replication monitoring information providing : 
 - the number of unresolved naming conflicts since last startup : unresolved-naming-conflicts 
 - the number of resolved naming conflicts since last startup : resolved-naming-conflicts 
 - the number of resolved modify conflicts since ast startup : resolved-modify-conflicts
 
Note that modify conflicts are always resolved automatically.
Also note that these counters are reset when the server is restarted.

This commit also include a new test for modify conflicts with some checks of the counters values
and update to the naming conflict test in order to test the counter implementation.

Thanks again to Chris