title: A bug in Scalatest 'DoubleTolerance'?
body: <p>I've encountered failing tests which in all of my understanding should pass. Am I missing something obvious, here?</p>
  
  <pre><code>import org.scalatest._
  
  class xxxTests extends FlatSpec with ShouldMatchers {
    import math.{Pi =&gt; PI}
  
    "" should "(this should pass)" in {
      assert( 0.0 === 0.0 )  // ok
  
      (1e-100) should equal ((0.0) plusOrMinus 1e-5)    // FAILS!!!  "1.0E-100 did not equal DoubleTolerance(0.0,1.0E-5)"
      (1e-3) should not equal ((0.0) plusOrMinus 1e-5)    // ok
      (0.0) should equal ((0.0) plusOrMinus 1e-5)    // FAILS!!!  "0.0 did not equal DoubleTolerance(0.0,1.0E-5)"
    }
  }
  </code></pre>
  
  <p>I've experienced this with both Scalatest 1.8 and 2.0M4.</p>