Remove unused configs pybasedir and bindir

Both options are leftovers from the initial Cinder fork and are not used
for anything useful.

Also use a sane default for 'state_path' which pointed to $pybasedir and
now points to '/var/lib/manila'.

Change-Id: I95d824cd81c98815fde6c312b0e4fd38fb4c88e9
Merge "Remove unused configs pybasedir and bindir"