The image type was not taken into account due to the missing PrepareKernelAction

Signed-off-by: Rémi Duraffort <remi.duraffort@linaro.org>

Most test directories are called "tests" while two where called "test". Keep
only the first form.

Also fix coverage computation as lava_dispatcher.actions.test was not computed.

Signed-off-by: Rémi Duraffort <remi.duraffort@linaro.org>

- Unify the bootloader interrupt action for all bootloaders to use
- Check for error messages throughout bootloader interaction
- Be reasonably confident that failures after bootloader commands, are kernel

Change-Id: Ib8413baf5667dec4d487a9ca40f9b222be3c0b19

Change-Id: I098edd9edfeb968b303eaedc6afb6654e43b4b98

LAVA-1066 Some jobs fail without logging useful information which
may appear on a connection. Add support for reading feedback
during Finalize.
Extend support within Finalize to finalise all connections,
not just the shared one.

Change-Id: I4162d95e955ffe0ed0bda775b80eb171ea7ef438

This changeset implements boot with a network block device.
Initial steps are equal to tftp+nfs but instead of nfs this
method depends on an nbd-client started on the target within
the initrd. The rootfs is served on the slave through xnbd-server.

This setup is needed when the target system needs e.g.
extended file attributes like security labels to boot.
In this case cpio.gz and nfs do not work and both the initrd and
the rootfs need to be a full filesystem (e.g. ext4).

Boot sequence:
 DL -> tftp -> initrd (nbd-client+pivot_root) -> rootfs(nbd)

The implementation reuses as much as possible from the
existing tftp+nfs workflow. The startup of the xnbd-server
and its proper teardown required the use of an action/protocol
combination (similar to lxc).

The xnbd-server will use a random port (unless specified).
A helper function has been added to network.py.

Change-Id: Ibbaa10b4bdab49d9cc95d9b1c6cb3d67f848760a
Signed-off-by: Jan-Simon Möller <jsmoeller@linuxfoundation.org>