Added FSEvents::Stream#run as a way to easily run the stream.

This merely calls OSX.CFRunLoopRun, which passes control to the Carbon framework.

lib/fsevents/stream.rb

@@ -92,5 +92,9 @@ def shutdown
       invalidate
       release
     end
+
+    def run
+      OSX.CFRunLoopRun
+    end
   end
 end

spec/stream_spec.rb

@@ -545,6 +545,17 @@
       @stream.shutdown
     end
   end
+
+  it 'should run' do
+    @stream.should respond_to(:run)
+  end
+
+  describe 'running' do
+    it 'should enter the run loop' do
+      OSX.expects(:CFRunLoopRun)
+      @stream.run
+    end
+  end
 end
 
 describe FSEvents::Stream::StreamError do