Update to 2.17.0.

• Drop the need for PORTSDIR in dependencies [1]
• Allow a trailing ':' in URLs [2]
• Check to make sure the value(s) of SUB_FILES is healthy [3]
• Expand variables on all sides of the dependency tuple [4] (this last change is rather big, and thus bumping minor version)

PR: 208272 [1]

		207843 [2]
		207477 [3]
		206061 [4]

Submitted by: amdmi3 [1]