x11-fonts/libFS: Update to 1.0.8

Update x11-fonts/libFS to 1.0.8
This release contains a fixes for a bunch of sign comparision warnings,
and changes to the build system

add LICENSE and LICENSE_FILE
pet portlint a bit, move USES= earlier
use INSTALL_TARGET=install-strip to strip binaries and files

Changelog:
https://lists.x.org/archives/xorg-announce/2019-March/002970.html

Sponsored by: B3 Init