Make sym-link processing optional

[zanerock]

Overview

Currently, sym-link files and dirs are traversed just like regular files. This is usually what the user wants, but can be a security concern so we should make them ask for the behavior explicitly.

Deliverables

• add --follow-symlinks invocation option. If present, then processing behavior is as current.
• If not present, then remove the -L option from find and test any files found to see if they are symlinks.
• If a search fails and the --follow-symlinks option was not set, advise the user that --follow-symlinks must be used if any of the target files or valid search directories are symlinks.