Implement the IMAP module

[artpi]

We need a new module for imap client:

• We want credentials in settings
• We want to check that inbox every minute via wp-cron. A pattern for these periodic checks in in evernote sync module
• Lets get all emails in that email inbox. For each email, lets trigger a new action
• Lets hook into that hook and log the email to error_log

In the future we will want to process these emails and react to them.

We also want a method to send email from this email inbox using phpmailer

We will also want to have access to attachments attached to emails in this inbox, but for now lets only log subject, sender and body.

The settings should be using the settings module