docs: add back build to remote api v1.10 & v1.11

This adds back the rm query parameter to the remote api docs for api
v1.10 and v1.11.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
bump remote api to 1.12 & add --force-rm to build

This adds a `--force-rm` flag to docker build which makes the Docker
daemon clean up all containers, even when the build has failed.

This new flag requires that we bump the remote API, so we also bump the
remote API version.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
integcli: add getContainerCount utility function

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
integcli: test container removal for failed builds

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
default to deleting images via the remote api

This makes the remote API version 1.12 and newer default to
automatically deleting intermediate containers when the build has
succeedeed.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
integcli: add tests for build --rm

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Add new consolidated mkimage scripts

These new scripts are streamlined such that, for example, "contrib/mkimage/debootstrap" is _only_ responsible for filling a directory with the results of running debootstrap, and it can accept any arbitrary arguments.

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Add deprecation warnings to the mkimage scripts that are have consolidated mkimage implementations

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
devmapper: Don't enable discard during mkfs.ext4

There is no reason to do discard durink mkfs, as the filesystem
is on a newly allocated device anyway. Discard is a slow operation,
so this may help initial startup a bit, especially if you use a larger
thin pool.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Merge pull request #5990 from alexlarsson/no-discard-mkfs

devmapper: Don't enable discard during mkfs.ext4
Merge pull request #5967 from tianon/consolidated-mkimage

Add new consolidated mkimage scripts
Merge pull request #5839 from unclejack/improve_build_rm

add --force-rm to clean up after a failed build