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, I've tried that, but if you do
```
AGM_Medical_AllowNonMedics = 1;
if (AGM_Medical_AllowNonMedics) then {
```
it throws an error.