slight improvements to mind the gap

mind the gap added to the default

add london ug

The whistles are now less annoying and more varied.

Tweaked default settings and their docu.
Added "mind the gap" to some German local trains for a laugh.

more versatile settings: different open and close door sounds for different sound sets

add clacks to certain clackless waggons so more trains will make the station master whistle

new settings and london underground wavs

first