Multipart body parsing of hyper responses

Examples

To run the examples, the env STREAMURL must be set. To see some output, set env RUSTLOG={example}=debug

TODO

Some camera streams seems to be implicit multipart. I.e they send a continous stream of jpeg responses. This is easily handled by looking at the response header. If the header is non multipart we just continously parse multipart chunks from it. Make sure Hyper does not already do this.....