various cosmetic changes

NOTE.
I'm leaving vsliver_vs.py untouched
However, in set_resources, most of the calls to the lower level (vserver/vserverimpl)
methods are called unprotected by a try/except
If any of this fails, then the exception gets caught in accounts:_run only
and this might prevent correct operations
to make things worse, in such a case the error messages printed by vserverimpl
might get lost in daemon mode
So a cleanup in this area might be most useful