Issue in walking XML error nodes

[pbrisbin]

Looking at the code, it seems like this engine suffers the same logic error in XML node walking as codeclimate/codeclimate-csslint#18.

The result of this bug is that issues present in any file are reported as present on all files. This makes the engine basically unusable.

[jsippel]

I believe that the version in the beta channel does not have this issue.