ipcontroller/ipengine use the new clusterdir.py module.

Minor revisions to ipengine_config.py

The ipengine script has been refactored to use the new config system. It is also now a formal Application: IPython.kernel.ipengineapp

Removing old ipcontroller.py

Finished refactoring ipcontroller to be a proper application. * The :command:`ipcontroller` script has been refactored into a proper IPython application that uses the new config system. This also introduces the idea of an application directory, which for :command:`ipcontroller` is :file:`cluster_<profile>` by default. This cluster directory has the config file, the log directory and the security directory for the controller and engine.

Work on ipcontroller. * The IPControllerApp now uses ApplicationWithDir to manage the app_dir. * The setup.py script and ipcontroller script have been updated to use the new IPControllerApp. * launch_new_instance created and being used.

Moving ipcontrollerapp.py to its new location.

General work on the kernel config.

Remove usage of deprecated .message attribute of exceptions. This fixes https://bugs.launchpad.net/ipython/+bug/407836. The .message attribute of Exception is being deprecated in Python 2.6. All new code should simply use args[0] for this purpose. There are still a few places that modules in external use this. Hopefully these will be updated soon.

ipapi.get now returns None if there are no InteractiveShells running. It used to simply raise an IndexError, which was bad.