Implement new admin command /report and supporting commands

[dGr8LookinSparky]

Via @Shuffle
Basically, I'd like to request that the commands /report, /reportlist and /reportdelete be added to the server.

In case you're unaware of what these commands are, they basically do exactly what you'd image: they report a player. The syntax is simple: !report [name] [reason]. If Player A did !report Player B TK/Bleed, it would save both of their IP addresses, their GUIDs, the reason given (TK/Bleed) and the date of the report.
The commands !reportlist and !deletereport are admin exclusive, and can be used to see the various reports from different players.

It's basically just useful in case you want to remember a particular IP address of a troublemaker, or just for general use, ie: finding specific people in the logs.

https://github.com/AlienHoboken/Tremulous-X-Server

[dGr8LookinSparky]

Include a reference to the server demo of the match and time in the match that the report was made, also include a reference to the server side demos directly before and after the match the report was submitted.

[dGr8LookinSparky]

Additional reference: https://gitlab.com/tremulous/tremulous-scribble-3/issues/169