Merge branch 'ttl_2_seconds' of https://github.com/Alexqw/zfSnap into Alexqw-ttl_2_seconds
Merge branch 'valid_ttl' of https://github.com/Alexqw/zfSnap into Alexqw-valid_ttl
Merge branch 'small_fixes' of https://github.com/Alexqw/zfSnap into Alexqw-small_fixes
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
Update readme
Rename README to README.md
Update README.md
Create FSExists function.

Comes with tests
Check if pool/fs exists when creating snapshots

Removes a grep call as well.

Two integrative tests disabled. Should be reused when we have a proper
test environment in which we can create and destroy filesystems and snapshots.