Decode Content-MD5 with base64, not hex

Also fix crypto fun names, though I haven't yet
seen a situation where that function is called.
More discussion of the issues can be seen
[here](https://github.com/basho/webmachine/issues/116).
Add another stream format with known Content-Length
Add known_length_stream to decision_core
Add known_length_stream pattern to wrq module
Add func for streaming without prefixing chunk lengths
Provide empty stream for HEAD reqs w/ known_length_stream
Merge pull request #117 from basho/wrd-base64-content-md5

Decode Content-MD5 with base64, not hex
Merge pull request #118 from basho/wrd-content-length-with-streaming-rebased-1

Wrd content length with streaming rebased 1
Remove app, be more unity instead
Merge branch 'master' of github.com:basho/webmachine into ms-add-tests