sysutils/clean: Add UNKNOWN License

The license text can found in main.c.
Prefer DISTVERSION.
Refresh patches utilizing REINPLACE_CMD.
Adopt port.

Approved by:	bofh (mentor)
Differential Revision:	https://reviews.freebsd.org/D44179

sysutils/clean/Makefile

@@ -1,15 +1,25 @@
 PORTNAME=	clean
-PORTVERSION=	3.4
-PORTREVISION=	1
+DISTVERSION=	3.4
+PORTREVISION=	2
 CATEGORIES=	sysutils
 MASTER_SITES=	SF
 
-MAINTAINER=	ports@FreeBSD.org
+MAINTAINER=	uzsolt@FreeBSD.org
 COMMENT=	Automatically remove unwanted files
 WWW=		https://sourceforge.net/projects/clean/
 
-USES=	tar:bzip2
+LICENSE=	UNKNOWN
+LICENSE_NAME=	unknown
+LICENSE_TEXT=	Permission is granted to copy, modify, and use this as long as this message remains intact.
+LICENSE_PERMS=	dist-mirror pkg-mirror auto-accept
 
-PLIST_FILES=	bin/clean share/man/man1/clean.1.gz
+USES=		tar:bzip2
+
+PLIST_FILES=	bin/clean \
+		share/man/man1/clean.1.gz
+
+post-patch:
+	@${REINPLACE_CMD} 's|$$(PREFIX)|$$(DESTDIR)$$(PREFIX)| ; \
+		s|man/man1|share/man/man1|' ${WRKSRC}/Makefile
 
 .include <bsd.port.mk>