Improve bind mount in development mode

[mfhepp]

The run_script.sh script takes some lengths to detect and handle overlaps between the src/ and the output/ volumes, and problems caused by potential cycles.

It's likely better to use a dedicated mount point /mnt/output/ for the output directory. To be analyzed...

Also, a better understanding of Bind Propagation in Docker and Shared Subtrees in Linux will help:

• https://docs.docker.com/storage/bind-mounts/#configure-bind-propagation
• https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt