First crack at constructing historical snapshots.
Checkpoint: DAG-based revision history with deltas
CHECKPOINT: Partially implemented VC with snapshots.
Just whitespace.
Enhance benchmark tool: only pull targets if we don't have them.

This assumes that the target is actually on the stack, which may
not necessarily be true.
We don't have to write the index for Pin and Unpin.
Wrap debug messages in sub{} to improve performance.
Add commentary about our indexes.
More commentary about our indexes.
Experiment with disabling synchronous writes.  This gives a huge performance boost.
Commentary about potential optimization.
Reconstruct $pinto on each iteration, to better simulate real world.

I'm not sure, but this may cause it to close and re-open the db
connection on each iteration, which is more like what would really
happen if you used the pinto command line.
Prevent annoying duplicate error messages when die-ing.
EXPERIMENTAL: Using savepoints to break work up.

The idea here is to allow you to continue, even if a distribution
causes you a problem along the way.  Not sure if this is a good idea.
Can't be sure every exception is an object.  Need to do something smarter.
Can't assume there will be a key to search by.
Super cool nofail option.

This tells Pinto to keep going even if pulling/adding one
distribution failed.  It might make sense to offer this
for each dependency too, not just the top-level dists.
Fix tests, following earlier changes to placeholders.
Note to move the 05-util test.
Create log dir during initialization.

I'm not sure if this step got deleted along the way
and I never saw the test failure.