Statistics: At long last, the monster statistics commit.
We finally have a stable, documented and uniform codebase for statistics.
This resulted is removal of several functions in other classes too.
There are a few new reports, but mostly, each report is a lot more flexible.
-Security: This is to be implemented directly in the Statistics class,
by forcing restrictions to the selected nodes and network.
-Support selecting multiple users for a report.
The code and SQL queries support it, but the UI doesn't.
An easy and quick way would be to simply parse a coma-separated list.
Comment are off course welcome!