Improved ERS memory handling

On shutdown the ERS will loop thru leftover managers and clear them according to each manager's settings, while also printing errors according to each manager's settings.
Will also help pinpoint the causes of http://hercules.ws/board/tracker/issue-8093-memory-leak-after-stop-server-cant-fix/ and similar issues.

Signed-off-by: shennetsind <ind@henn.et>