Fixing header decoration in `start()`, directing `range` requests to the 'handler', decorating `accept-range` header from `respond()`
Implementing `206 - Partial Content` on uncompressed responses
Implementing `206 - Partial Content` on compressed responses (files on disk)

Fixing alignment
Decorating `Content-Range` & fixing `Content-Length` headers in `respond()` for `206` responses
Merge pull request #274 from avoidwork/AcceptRanges

Accept-Ranges / Range HTTP header implementation for files on disk