Seperate different functions into seperate plugins

Api calls and client preferences go into base
p, pall, stop, etc go in player
donator intros into donator_intro
map change themes go into map_change
Implement natives
Implement the music player plugin
Remove plast
Only call map change music if IGA is enabled
Implement donator intros
Fix Native_MapTheme looking at wrong argument
Mention that changin volume won't affect current song