SES-1675 : Add DROP_LONG_LITERALS and LONG_LITERALS_LIMIT parse settings

These settings were the original usecase for extending the ParserConfig
interface to support arbitrary settings, but for some reason they were
not implemented before the issue was closed.
Merged in ansell/sesame/SES-1675-longliterals (pull request #92)

SES-1675 : Add DROP_LONG_LITERALS and LONG_LITERALS_LIMIT parse settings