Added extensible prompt facility to io.sys and wrote a small unit test
Added extensible request and response for context managers
Applied some pep8 spaces which were lacking
changed request_prompts to prompt_responses
Add support for #930 - specify an abort handler exception
Document the abort_exception env_var
Handle connection failures due to server load

SSHException with "Error reading SSH protocol banner" is raised when
sshd is unresponsive but Fabric treats it as an auth failure. This patch
fixes this by treating it as NetworkError.
Add a changelog entry for #948
Add troubleshooting doc
Merge branch '1.6' into 1.7
Merge branch '1.7'
Add minor releases to changelog description
Merge branch '1.6' into 1.7
Merge branch '1.7'
WIP w/ intermediate data nodes
Start of real impl, still missing parts
MOAR
Nuke prints
Unreleased shit
Reorg, ensure ancient changelog bits don't conflict badly