Refactor ide.callgraph slightly.

Makes more sense to build the call graph in one step and for get()
to be responsible for collecting the trace.
Have matlab2json use Natlab.jar, not Natlab.sh.

Natlab.sh hardcodes a path to Natlab.jar, which can cause trouble
since the directory has a different name depending on whether we're
in the VM.
Fix typo in instrument.sh.

Not sure why this was working in the first place, but from the command line
it fails with an error.
Refactor refactor.sh to be like instrument.sh.
Update mclab submodule.

In particular need
Sable/mclab@9d9c9f0d3bcf3bd2fe0d2e0289e974015d04328f.