Improve handling of domains that overlap with file endings (.py and .zip)

[fhightower]

.py is a valid TLD, but also the extension for python files. Is there a better way to handle domains ending with .py to differentiate them from python files?

[fhightower]

.zip is in the same boat - it's a common file-ending, so we need a way to determine the diff. between a file name and domain name.