Added 'batchName' and 'creationDate' properties to ClaimCode schema.
Add claim codes badge route now uses Badge#generateClaimCodes() if needed.

This ensures that the requested number of claim codes is actually created,
rather than generating the requested number and potentially having some
of them collide with pre-existing codes.
Batch names can now be provided by the addClaimCodes badge route.
Admin users can now specify a batch name when creating claim codes.

Batch name is also visible as a column on the "existing codes" table.
Added "bulk actions" form at bottom of claim code management page.

Right now the only bulk action is "export open codes as plain text", which
the user can apply to all claim codes, or claim codes in a specific batch.
Added claim code printouts.

These don't quite look as awesome as jess' mockups, but they do contain
all the required information.

Note that the `OPENBADGER_CLAIM_URL_TEXT` environment variable must
be defined in order for the handouts to have a URL on them; otherwise
they just say "go to the website" rather than e.g. "go to csol.org/claim".

I believe this fixes #184.
Merge pull request #196 from toolness/issue-184-claim-code-batch-names

Add batch names to claim codes, printable handouts