Lots of fixes/changes

1) Global variables should be in UPPERCASE, function local variable in
   lowercase, to prevent function local variable overwriting global
   variable (issue with $ttl)
2) Make sure there is slash after zfs filesystem, before .* in pattern, when deleting
   snapshots recursive snapshots.

   This should prevent deleting snapshot from similar fs

   test/a@r
   testing/b@r

   pervious pattern was faulty

3) remove -e option
4) clean up some variables