Remove gencoide as a standard flag

This removed Genocide from the game. all calls to +f will fail and the flag is removed from the "Good" list. This is done in a protocol compatible way, clients will just think that Genocide is not on the map.
We also remove RogueGenocide plugin since Genocide doesn't exist as a flag.

This pull adds a new plug-in to replace genocide and includes the RogueGenocide  functionality for those servers that still want to use it (it just now has to be turned on specifically). The new plug-in uses a custom flag with the code "GO"