doesn't flag undeclared use of InternalError

[davepacheco]

The version of javascriptlint in master right now treats "InternalError" as one of the built-in globals, similar to RangeError or TypeError:

https://github.com/davepacheco/javascriptlint/blob/040bf5e429969ae42d976b570fd64c9e17fab20f/javascriptlint/lint.py#L30

This appears to be a non-standard class used by Firefox:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/InternalError

It would probably be better to remove it from the list of built-in globals and have people using Firefox add it as a definition in their project-specific configuration file.

Right now, if you have (say) Node code that uses an InternalError class, javascriptlint will fail to identify cases where that name hasn't been properly declared.