Add no-sync option to checkpresent.

Currently, if checkpresent is run and it determines that an inventory
is too old it will automatically perform an inventory sync.  This
may be undesired in various situations, so allow the user to
supply the --no-sync option to prevent this.
Provide progress monitor during uploads.

The progress monitor can be supressed with --quiet.
Add verbose archive list option.

The --verbose flag will print the id, name, last_seen, created.
Support meaningful exit status from actions.

If an action returns a non-None value, use it for the exit status.
Add suppport for storing and using hashes.

When uploading, store the sha256 tree hash into the cache so
that it can later be used to verify a glacier archive via
'sync'.

The cache will be migrated, and existing archives will have
their hash updated on the next inventory sync.
Implement glacier check command.

This command accepts a file and checks the following:

- It exists in the cache inventory
- It has been seen recently enough to be considered present
- The sha hashes match
Support providing mutliple files to upload.
Add support to 'archive check' multiple files.

This behave similar to 'md5sum -c' and will print
output for each file.  At the end, if there were any
errors they will be printed to stderr and a relevant
exit status will be provided.