man(1) can't handle compressed included files.

man(1) can't handle compressed included files.

	Some ports will install with compressed manpages. man handles
	this by looking for the .gz version of a man source file.
	It is also common to include other files with the .so
	directive where commands or functions share a man page.
	Traditionally ports have had to handle this by either not
	compressing the manpages, or using the _MLINKS macro in the
	port makefile to create symlinks to the actual source file,
	rather than using .so versions. Notably, the current version
	of Xorg port breaks. See ports/113096 and ports/115845.

PR:		bin/115850
Submitted by:	Callum Gibson <callumgibson@optusnet.com.au>
Approved by:	re@ (ken smith), grog@ (mentor)
MFC after:	1 week