AE: Fix menu sounds decreasing buffer(max 200 ms) and periodSize(50 ms)

After last commit, I broke menu sounds, cause of a too large buffer. The menu sounds problem has to be investigated separately. Until this happens, let us go back to save values. 

Advantage over the old values are, that periodSize and bufferSize scale with the sampleRate. The fix of the menu sounds is, that hopefully no one realizes 200ms waiting time in the menus.

I will look into menu sounds later, something like "drain when there is nothing playing" and don't eat silence if not forced - we will see.

@elupus: I hope the larger buffer can come back, as it is rather great for movie playback
@anssih: thx for review