Added parseErrorOccurred delegate and parseError method.
Added parseErrorOccurred delegate and parseError method.

Created delegate method to handle parseErrorOccurred which also sets
the value for parseError. If parseError isn't set then
when_parser_errors doesn't have any error to access when called, which
is confusing.

dam13n/BubbleWrap,hboon/BubbleWrap,fandor/BubbleWrap,earthrid/BubbleWrap,andersennl/BubbleWrap,mattetti/BubbleWrap