Add interceptor exclusion configuration

[zakhenry]

Sometimes a third party service might call an endpoint and expect a failed response, e.g. authentication failure.

Currently, that API could add the skip interceptor param to the request method, but that is unrealistic as that API might not know about angular-rest-adapter.

Add a method on the configuration object, and/or a method at runtime to allow certain endpoints to be whitelisted from the interceptor.

E.g.

ngRestAdapter.skipInterceptorRoutes([
    '/api/auth/*',
])

Note that the pattern should support wildcard characters.