Add back detection for mysql and sensitive files.
Add back detection for mysql and sensitive files.

Add back detection for mysql and sensitive files that was removed in the
previous commit. A new macro proc_is_new adds a condition on how long a
process has been running.

A new rule triggers if the process is not new and tries to open a
sensitive file. This handles cases like mysql, where it *does* read
/etc/passwd on startup but shouldn't really open it afterward.

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