Fixes readerascii usage for files with no newline

• removes debugging cout left in previous MR
• tweaks ReaderAscii::read_event logic slightly so that an event is not considered successfully read by default until we know we have an event to read. This means that calls to read_event after the last event have been read are not considered to have read an event. To supress an error message, we now only check if event parsing failed if we are reading an event (which is no longer the default state before any parsing has been done).
• Adds testIO31 which checks that the right number of events are read from a file without a trailing newline