Script to automate Makefile.am updates for new/renamed tests

[airtower-luna]

Currently test configuration files in test/tests/*/ as described in the test implementation documentation must be manually added to EXTRA_DIST in test/tests/Makefile.am so they get included in distribution archives.

Likewise, tests need an entry in test_scripts in test/Makefile.am to actually be executed.

Create a script that automatically updates those lists based on the content of the test/tests/ directory when run. The script is meant to be run by developers as needed, followed by a manual commit. It should not be run automatically at any point or interact with git (except possibly to check if there are any changes).