added LICENCE
Revert "added LICENCE"

This reverts commit d1b0f305bc077ab18a964b05892cbc720b21a004.
LICENCE
Add unit test.
Fix for Darwin (Mac).
Revert "linux now has internal support for xattrs".

This reverts commit fe267a52f85cb48f31e61cfe2edd2a5e22d0f59b.
Unify Linux and Darwin (Mac) code.
Fix error handling on Linux.