Update to 2.17.16

• Check for USE_PYQT when USES=pyqt:5 is defined [1]
• Avoid more bogus direct command use warnings. Also try and fix some line numbers [2]
• Check for over-verbose use of magic MASTER_SITES_SUBDIRS [3]
• Do not complain about missing Created by: [4]
• Avoid checking direct command usage in embedded comments [5]

PR: 225615 [1]

		225612 [2]
		225503 [3]
		225781 [5]

Reported by: Jason Bacon <bacon4000@gmail.com> [4]