Add more links to useful resources
Add a link describing the `boot.cmd` format.
Install kernel modules

Without this step — with the .config provided by xen-arm-builder — the
bridge interface would not start because the `bridge` module would not
be present.
Merge pull request #215 from Chris00/modules

Install kernel modules
Merge pull request #214 from Chris00/more_links

Add more links to useful resources
Increase dom0 memory to 256M

Without this `apt-get install openssh-server` is excruciatingly slow.
Point to xen-arm-builder for boot.cmd

This takes care of the synchronization of the blog post with the
xen-arm-builder.  We also point the the correct file for the
Cubietruck.