Class DelayedGuessedSpawningStrategy

      object --+    
               |    
SpawningStrategy --+
                   |
                  DelayedGuessedSpawningStrategy

SpawningStrategy that uses Twisted if it is present in ``sys.modules``.

This SpawningStrategy tries to do the right thing my looking at
the contents of ``sys.modules``: if "twisted" or a module of that
package is loaded when the first spawning method is run, it will
use the Twisted spawning strategy. Otherwise, it will use a simple
fork/exec spawning strategy which does not depend on Twisted.

x.__init__(...) initializes x; see x.__class__.__doc__ for signature