Set local variable visibility in batch scripts

Set local variable visibility in batch scripts

Use SETLOCAL in batch scripts to restrict the visibility of variables
that are set in the script to the script execution. Otherwise the variables
will also be set in the calling shell. That is not a problem when a script
is executed by double clicking it in Windows Explorer. But now that the
scripts are changed so that they can be called on the command line from
other folders, they should also no clutter the calling environment.