Round limiter, per command access restrictions, other fixes/small requests

- Added the round limiter plugin from Ghoul.
- Added a standard method to check for whether a plugin is enabled, and to acquire its table.
- Replaced sv_say with sh_say.
- Added commands to change interp and move rate live.
- Added per map round limits.
- Server switch menu accounts for reserved slots when displaying the server population.
- Added the ability to force a delay at the start of a map before the game can start to allow players to load.
- Fixed tournament mode breaking things when disabled.
- Fixed reserved slots not changing the tag when a client with a reserved slot disconnects.