title: Clearing all user-defined objects in R workspace
body: <p>I'm working with Rserve via Ruby bindings.  It's pretty trivial to establish a connection to Rserve, and I assume its a good idea to persist that connection globally to avoid the overhead of tearing it down and re-building it as needed (I'm not operating in a multi-threaded environment).</p>
  
  <p>Since the objects defined will stick around, and potentially class with later operations, I want to clear them out.  I've seen:</p>
  
  <pre><code>myvar = 1
  rm(myvar)
  </code></pre>
  
  <p>However, I would rather re-initialize everything, to avoid having to manually keep track of whats defined.  Is this possible?  Is there a significant overhead associated with it if so?</p>