removing stale files
adding more core folks
updating overview to include two-process model
mention %matplotlib magic in mpl integration

Now that #3568 is merged, we should steer folks in that direction
mention --matplotlib flag, remove pylab references
updating shell mode - lots has been removed

but enough is still there to keep this documentation around
added more references to shell
fix cookbook URL
add label to the two-process section

there used to be a whole file which talked about the work-in-progress on
moving toward the two-process ZeroMQ model, and the qtconsole docs
reference it, but after that work was finished, the work-in-progress
docs were removed.
bind kernel events in Kernel.bind_events

avoids multiple-register of send_input event
remove any lingering raw_inputs on raw_input

There should never be more than one,
so ensure that is the case on creation.

closes #3710
Merge pull request #3716 from minrk/debugagain

raw_input fixes for kernel restarts

- fixes multiple event-registration causing duplicate messages
  after kernel restart.
- removes any raw_inputs hanging around that might have been left by kernel restarts.

closes #3710
remove specific # of years, at @minrk's suggestion
Merge pull request #3709 from ivanov/docs-cleanup

Docs cleanup