x11/libXcursor: Update to 1.2.0

Update x11/libXcursor to 1.2.0
This release adds ~/.local/share/icons to the front of the default
cursor path in the library in support of the XDF user data dir.

pet portlint by moving USES= earlier
add LICENSE_FILE

Changelog:
https://lists.x.org/archives/xorg-announce/2019-March/002972.html

Sponsored by: B3 Init