x11/xrandr: Update to 1.5.1

Update x11/xrandir to 1.5.1
add LICENSE_FILE
Upstreamed has switched to xz for the source tarball
This is a maitnenance release

Changelog:
https://lists.x.org/archives/xorg-announce/2019-August/003018.html

Obtained from: FreeBSD Graphics Team development repo

		https://github.com/FreeBSDDesktop/freebsd-ports/tree/feature/xorglibs