Potential fix for lack of uniqueness in validator ids

Potential fix for issue #51. I added a custom filter to remove backspaces from the namespaced class name and then use the combination of classname, fieldname and the counter to hopefully ensure uniqueness. Fieldname and counter were close but if two services in the same api used the same field names in the same positions, the second one would not work in the UI. This *should* be more unique and allow the UI to behave as expected. The input.name part may not even be needed as I expect there's already validation ensuring that you don't enter the same input name more than once per service.

As a side note, I tried replacing \ with : but it seems angular or something didn't like toggling things that had colons in the id, but taking out the namespace separators worked.