Add build support for suites

[smarr]

With #58, we only get support to build VMs, but would be good to be able to build suites, too. For instance for Java.

It would also be good to do building on a separate thread, to show for instance a keep a live message. And generally, we should indicate that the build is done to the user, because for Topaz it takes 25min.

• build for suites
• keep alive note (Support list of build commands #96)
• user info about build (done with Improve error messages #85)
• support list of strings for suites and VM build commands (Support list of build commands #96)

[smarr]

First element is addressed with #78.

[smarr]

The support for builds is not yet good enough.
Sometimes, a VM has multiple dependencies that are shared.
So, build: should be changed from a simple string, to a list of strings.