Rename mkimage-debian.sh to mkimage-debootstrap.sh to more clearly reflect its true function
Refactor mkimage-debootstrap.sh to be much more full-featured

This includes the following:
- options to control certain parameters
- an option specifically for creating tarballs directly, esp. for dockerbrew
- the addition of the updates and security repositories for Debian images
- the addition of the universe, updates, and security repositories for Ubuntu images
- more correct tagging of Debian images
- tagging of Ubuntu image versions (12.04, 12.10, etc) and latest tag for LTS
Merge pull request #2222 from tianon/debootstrap

Renamed and refactored mkimage-debian to mkimage-debootstrap to more clearly reflect its true function
Add -nostdin and -proxy to docker attach, allow arbirary signal to be sent via docker kill api endpoint
Allow attach from `docker start`
Add host integration script generation
Update doc with host integration
Add POSIX shell version of host_integration/manager.go in the style of hack/make.sh
Rename host_integration to host-integration for consistency
Fix issue killing container while sending signal
Fix rebase issue
Update docs
Fix attach race condition, improve unit tests, make sure the container is started before unblocking Start
Update documentation
Fix issue with autoremove
Add a chan to hijack() to block until the hijack is completed