Relate on import

This attempts to relate emails better on import from user's email accounts.

First I match based on known email addresses, using precedence:

Contact > Lead > User

From > To > CC

I also set Status = Sent, when the email has been imported to Espo via a Users IMAP folder. (We don't scan Inbox we scan an 'Espo' folder.

Then I check for a MesssageId which matches the format set in 0299f300 and use that information if available. This means emails link against Cases / Opportunities automatically on import.

I also remove the case number feature from subject lines as auto-relating takes care of this.

Some of these changes might not be deemed relevant but here they are anyway.