Install manual pages to the correct location.

Index: novprog.pro
--- novprog.pro.orig
+++ novprog.pro
@@ -90,7 +90,7 @@ macx {
 	qm.CONFIG += no_check_exist
 
 	man.files = doc/novprog.1
-	man.path = $$DATADIR/man/man1
+	man.path = $$PREFIX/man/man1
 
 	INSTALLS += target icon desktop appdata qm man
 }
