AGM_Parameters used on AGM_Medical

Implemented the use of AGM_Parameters on AGM_Medical. It removes a lot of checks from the medical functions, as the variables are always initialized by the server on pre-init.
@commy2, if you do that there's no way to distinguish between a boolean and a numeric parameter. This way is not perfect, but how many times you really need a variable to hold the string "true" or "false"?