more structure in parser exception

[thecere]

I'm currently parsing the exception messages to derive column/lineno values. This is obviously insane so I propose give the exceptions some structure by adding lineno, col and the rest as exception attributes.

Candidates are JsonPathLexerError and stuff like Exception('Parse error at %s:%s near token %s (%s)' % (t.lineno, t.col, t.value, t.type))