Full support for all PURL response types

[fabiante]

PURL supports a couple of response types, not all are currently interesting to this project. Still, this is a tracking issue to discuss if support is required at some point.

Taken [from here]https://purl.archive.org/help) PURL knows these types:

Status	Desc	HTTP
301	Moved permanently to a target URL	Moved Permanently
302	Simple redirection to a target URL	Found
303	See other URLs (use for Semantic Web resources)	See Other
307	Temporary redirect to a target URL	Temporary Redirect
404	Temporarily gone	Not Found
410	Permanently gone	Gone

Wikipedia has more details on these responses: https://en.wikipedia.org/wiki/Persistent_uniform_resource_locator#Types