In this branch, the 0th level in the KB is a normal VMS, which leads to 
problems when and how to insert samples into the 0th level, because 
fully dependent models of a new model then get timestamps intersected 
sideways, or alternatively the 0th level is not available for a new 
model, which then needs a buffer-VMS somewhere else. Master branch will 
get a different style of level 0 now.