Tweak to make start.model.runs() wait for remote jobs.

OK, so fairly new to git, completely new to pull request workflow... bear with me.

I made this one small change to start.model.runs.R so it would wait for my remote job on geo.bu.edu. Before the change, it would fail with an error. A few more details are in the commit message.

I put this on its own branch (trivial for so small a change, or still recommended?), and supposedly am offering that branch as a pull request... now.