Add support for DOWNLOAD_URI option.
* Fixes some comments that were no longer accurate.

Conflicts:
	modules/auxiliary/gather/apple_safari_webarchive_uxss.rb
Rename DOWNLOAD_URI -> DOWNLOAD_PATH.

Conflicts:
	modules/auxiliary/gather/apple_safari_webarchive_uxss.rb
Update print_status labels.
Land #1777, usability fix for Safari module