Make __iterator__ and __proto__ non-fatal errors

Although use of either of these identifiers is clearly an unconditional
error, neither presents a problem parsing the file and shouldn't prevent
the reporting of subsequent errors.

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>
Make incorrect setter parameters a non-fatal error

Like incorrect getter parameters, if an incorrect number or name of
setter parameters is encountered, report the error unconditionally but
continue processing the file.

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>