Do not create a junction (soft link) for files
Do not create a junction (soft link) for files

When symlink_or_copy/2 cannot use file:make_symlink/2 on Windows due to the
user lacking SeCreateSymbolicLinkPrivilege it tries a fall back.

Detect the source type and use an appropriate fall back:
* junction for directories and,
* copy for files.

Improve error detection in win32_make_junction/2 and make it repeatable when
the target exists

erlware/relx,tsloughter/relx,lrascao/relx