change default to SUSE Cloud 4

Most people will be working with version 4 now.
Merge pull request #76 from aspiers/default-to-version-4

change default to SUSE Cloud 4
Sync mkcloud job

There are improved descriptions, and the default value for
cinder_conf_volume_type is empty so it can computed by the script.
When rebooting nodes, wait for a valid state and not just ssh connection

Previously, we were just looking that ssh is on, but we need to wait for
crowbar_join to have completed before going on.

As this will take longer, the timeout is also increased.
qa_crowbarsetup: Add function to bind mount dir

This can be used later to use local repositories.
qa_crowbarsetup: Add path to extracted Cloud isos

The paths to the extracted cloud product isos are needed for local
repository support.
qa_crowbarsetup: split GM3

plus some code cleanup
create-vm: Add extra options for nic and disk

Add parameters to define extra options for network interface and disk.
This is needed to setup a VM which is later used to boot a Xen kernel.
Xen does not understand virtio so to use the VM to boot a Xen kernel,
add e.g. "--disk-opts bus=sata --nic-opts model=e1000".
qa_crowbarsetup: Allow bind mounts for local repos

Optionally use local bind mounts instead of nfs when local repositories
should be used.
qa_crowbarsetup: Local repos handling for Cloud

Add local repository support for the cloud iso image.
qa_crowbarsetup: Cleanup repositories

If local repositories are used, cleanup all available repositories so no
remote repos are used.
qa_crowbarsetup: Restructure sles repos handling

Move SLES repository handling to single function and add local
repository support.