Update post-processor.html.markdown

Fixed some typos in the interface{} mentions.
scripts: Fix slight bash error
Updating the googlecompute builder documentation.
scripts: devcompile works properly in Cygwin
packer: don't crash if arg is empty [GH-832]
Fixed typo in qemu documentation
provisioner/ansible: upload playbooks correctly

`Provision` calls uploadFile on each path in playbook_paths, but
playbook_paths can only contain directories, per bf7530ca28.

This changes `Provision` to call uploadDir instead.
Update cHANGELOG
Add more special scancodes
Fix tabs vs spaces
Update CHANGELOG
HTTPDownloader uses UserAgent from DownloadConfig
StepDownload uses packer version as user agent
Update CHANGELOG
Do some forward porting of the old work of
mitchellh/packer's docker branch. #774
Rename docker post processor to docker-push.

Implement login to a docker registry, error handling
Finish up parameter parsing and validation.

Login to a docker index now works, ready for
implementation of the actual push logic.
Add docker-import post-processor.

Implemented initial working version
of Docker image importing code. #774
Start adding dockerfile provisioning to docker-import post-processor #774
docker-import post-processor, add TODO #774