Log unzip results by comparing destination contents.

Compare the actual destination directory contents for result logging
rather than relying on the COM object path builder. This works around
potential 260 character path length issues.
Log files added & modified by unzip process.

Extracted the logging logic into a (hopefully) reusable function that takes a script block to run. The target file structure is compared before and after the script block is run.
Fix syntax error in modified file logging.
Make file change comparison take into account Name and Size.

This should help take care of detecting changes even when there is weirdness with timestamps.