[bug] Fixing buffered streams to proxy properly

Fixes #109, #125
[fix] Opt in only content-type and content-length headers
[minor] Adding a comment for request header fixup
Merge pull request #126 from rackspace/newBufferedStream

[Rackspace] Refactoring Inline Authentication for Streams (Upload/Download)
[version] pkgcloud version 0.7.2
[bug] Fixing buffered streams to proxy properly

Fixes #109, #125
[Rackspace] Standardizing Auth on Openstack Keystone
[log] Adding a bunch of log emits for debugging
Adding keys support to rackspace provider
[minor] package.json cleanup for v0.8
[minor] Fixing up deltas after a rebase from master