Added a clear and a display random stat functionality

[weagle08]

The clear command requires a server restart. That was the best approach in my oppinion for a command that should be used pretty in-frequently. It requires this because of how the events self register on import. Leave me suggestions if this is not ideal.

[ForestOfLight]

Thanks for contributing! A few things before I can approve this:

• Please remove the CMD_CLEAR & CMD_RANDOM variables. They reduce code duplication, but I've been planning to make them all into an enum once proper custom commands are good enough. For now, adhere to the current setup.
• Not sure the clear command is a good idea. Did you have a specific time it would be useful instead of "reset all"?

[weagle08]

So my server needed a way to fully clear the accumulated stats in the stat list for use when playing simple stat poker. Without fully clearing you get a lot of stats that have not been incremented at all.

[ForestOfLight]

Ah- this is on my backlog for StatisticDisplay. Really what you need is a better way to look through the available statistics. The current listing command is basically unusable because of the volume of characters.

[ForestOfLight]

Stats are now much more easily searchable as of 1.1.7. Does this solve the need for a clear command for you?

Happy to merge the random command as long as the bulk of the logic is in its own method.