title: How can I invoke an Albacore rake task in a multithreaded way?
body: <p>I have a set of tasks in a Rakefile.  I use <code>MultiTask::invoke</code> in order to invoke them in parallel, and it seems to work fine.  These tasks eventually all share an Albacore task (an <code>exec</code>).  This <code>Exec</code> task seems to have some kind of a bottleneck, whereby it runs in serial instead of in parallel.  Is there some way to force Albacore to use <code>MultiTask</code> in order to run my <code>Exec</code>s in parallel?</p>