new: put name of project into generated zar.json

This way, 'zpm new foo' will create a zar.json with 'foo' in the
zar['meta']['name'] field.
new: strip trailing white space from generated zar.json

The JSON generated by json.dump has lots of trailing white space. We
should not let the user start with such a crufty file.
new: include args placeholder in generated zar.json
new: keep ordering in generated zar.json

Before, we just kept the zar.json template in a normal dict. Since a
dict has no ordering, the generated zar.json did not look like the
input dict.

We now keep the template as an OrderedDict. That way we can present
the keys in a "nicer" order and ensure that the generated zar.json
looks more like our documentation.
Merge pull request #80 from mgeisler/zar-json-template

Improve zar JSON template