bump(sys-libs/libcap): sync with upstream

This version doesn't install conflicting files in /lib64 and /usr/lib64
Merge pull request #73 from philips/bump-e2fs

bump(sys-libs/e2fsprogs-libs): sync with upstream
Merge pull request #74 from marineam/symlink-usr

bump(sys-libs/libcap): sync with upstream
bump(dev-lang/go): sync with upstream