Output generated PDFs to a folder

[deosrc]

Adding this as a draft just for visibility at the moment as it requires further testing and cleanup. Feel free to close if you prefer to wait or let me know if you have other plans for this.

Summary of changes are:

• Separate output processing to a module with separate classes
• Update logging/output to use logging library
• Add failure threshold to prevent a single error from halting the process
• Add support for SSL/TLS SMTP connections (without STARTTLS)