enfoce move and copy constraints

move and copy are very similar at test level, thus once properly
tested we might be able to merge code if appropriate
move directory with replace option

- few points still open and need to see how default fs implementation does
like what to do when moving a folder and there is a conflict in its content
- other tests (copy) still in progress are disabled
code format
fix copy directory with conflict & overwrite

unlike with move, we do not need to delete original entry
copy a file copies its content

+ fix another buffer copy issue in FileData
cleanup

EnumSet.of allows to remove all local varargs functions
replace few IllegalArgumentExceptions with custom ex.