added support for typeable URL in consent form (closes #29)

Removed password from the old consent URL (giving consent does not require password).
Also shortened the URL for the typeable version. This will be backward-compatible with the old clients (both URLs work). This will close #29.
@ben-jones, can you please review this?
I typically prefer two lines between functions, as you have here, and that is technically part of PEP8, but the rest of this file is formatted with one line between functions. Therefore, you should remove this line for consistency.