Bencode object key ordering in Debug and macros

[GGist]

When we serialize a Bencode object we are explicitly sorting the keys before encoding them so that we follow the bencode specification.

Since then, we have derived Debug for Bencode and allowed Bencode building via macros. In the current design we do not sort or validate data coming or leaving from these two avenues respectively. We would have to sort and verify the sorting of dictionary keys every time we do a Debug print or build a Bencode object via macros. It will be significantly easier (and maybe more performant depending on our usage) if we just made the switch from a HashMap to a BTreeMap in Bencode::Dict.

[GGist]

Since we have moved to using a BTreeMap as of #9 this is not longer an issue since keys are stored alphabetically.