ATS (Apache Traffic Server) Cert Reporting Tool Plugin

General description
-------------------

This plugin can be used to examine loaded certificates and logs related information onto disk.

The log format is as followed:
[time] [Lookup Name] [Subject] [SAN] [serial] [NotAfter]

To use the plugin, simply supply the name in plugin.config:
Example: cert_reporting_tool.so

And then send plugin messages to trigger reports/logs:
Example: `traffic_ctl plugin msg cert_reporting_tool.client 1` to log all client certificates.
