Add Default Headers Internally

[DavidBadura]

We should add the default headers internally, so the developer no need to know, that he need a specific path. And we should do this without a path: we should add our headers directly. auto-discovery should only used in user space.

Originally posted by @DavidBadura in #496 (comment)

[DavidBadura]

It is fixed, but we want to take another look to see if it is the best solution.