[Glass] tODE `bu snapshot` critical bug fix

[Dale Henrichs via Glass]

If you are using the dev branch of tODE and use the `bu snapshot` 
command, then you should pick up the most recent commit on the dev 
branchh which fixes the bug[1].

In light of the checkpoint discussion on this list yesterday, it's 
interesting that the bug popped up yesterday and the fix involves doing 
a checkpoint before snapshotting the extent ...

Anyway I don't normally announce tODE bugfixes on this list, but this is 
a critical bugfix for `bu snapshot` users ...

Dale

[1] https://github.com/dalehenrich/tode/issues/182