Cleanup minor issues in rest_api.md

- Spacing is now more consistent
- A few calls were slightly rearranged
Make the 'group' parameter explicit

I think this way is clearer, and it's actually shorter too.
Change 'label' to 'id' in rest_api.md
Add missing API calls to rest_api.md

Some of them don't have an obvious REST interface---those are marked at the
end.
Miscellaneous fixes to apidesc.md

These are similar to the changes made to rest_api.md.
Fix small typos in node_{register,delete}_nic
Revert 3340d0a

Change 'id' back to 'label' in rest_api.md
Also let 'id' -> 'label' in apidesc.md
Fix CLI help for headnode_{create,delete}_hnic
The model tests are unit tests, not functional tests.
Fix headnode_{create,delete}_hnic

First, fix the API.
Second, fix the typo in the CLI.

This should now work.

Closes #138
Generalize 'object_url' to take extra arguments

I used *args so that it would be backwards-compatible with previous usage.
The only difference, and it's minor, is that now all arguments are
urllib-quoted.  Tested with two- and three- argument calls.
Merge pull request #143 from zenhack/model-functional2unit

The model tests are unit tests, not functional tests.
Merge pull request #142 from gsilvis/api-headnode-create-delete-hnic-doc

Fix CLI help for headnode_{create,delete}_hnic
Add TODO to fix name of object_url
Merge pull request #122 from gsilvis/doc-api-cleanup

Doc api cleanup
Merge pull request #145 from gsilvis/cli-generalize-url

Generalize 'object_url' to take extra arguments
Add parameter 'nodename' to 'headnode_delete_hnic'
Add two more tests to headnode_delete_hnic
Merge branch 'devel' into bug138

Conflicts:
	haas/cli.py