Add function to fetch and clear imap errors

[drallan]

I was getting a lot of errors when fetching emails : Notice: Unknown: Warning: MIME header encountered in non-MIME message (errflg=3) in Unknown on line 0
The error message is emitted when you call imap_close(), or, in that function's absence, when the script ends. Call imap_errors() before that (to clear the error stack).

http://stackoverflow.com/questions/3378469/how-to-get-rid-of-error-messages-with-phps-imap-fetchstructure

call popServer->getImapErrors() to clear the error list

[drallan]

Seems to be a problem with the tests?
RuntimeException: Connection failed to 127.0.0.1,143: Connection refused