More work on the crash handler....
More work on the crash handler.
* Made a subclass of :class:`IPython.core.crashhandler.CrashHandler`
for each application we have. Each of these has a custom message
and uses the name and email of the appropriate personf for that app.
* Removed the :meth:`IPython.core.application.abort` method.
* Made small changes to how the crash handler is instantiated in
:class:`IPython.core.application.Application`.
* Tested the crash handlers.