fixed issue #741: documentation improvement
added HAS and HAS_NOT
check for null pointer for ROOTDIR
Merge remote-tracking branch 'origin/1.4' into devel

Conflicts:
	CHANGELOG
	Documentation/RefManual/Actions.md
	Documentation/UserManual/Foxx.md
	Documentation/UserManual/UserManual.md
	lib/ProgramOptions/program-options.c