Minor cleanup and bug fix.

* Moved KernelManager attribute management code in FrontendWidget into a mixin class usable in any Qt frontend. Registering handlers for message types is now trivial. * Made the Qt kernel manager signal interface more consistent with the revised message specification.

Merge branch 'master' of github.com:ellisonbg/ipython into newkernel

Fixing small bugs in ipcluster stuff. Recently, I changed the way traited classes were working to all keyword args in __init__. I had forget to update a few things to reflect this.

Reenabling output trapping in the kernel.

Moved a few things back to InteractiveShell. The following attributes were still needed in the base InteractiveShell class. * autoindent. This is used in runlines. * separate_in, separate_out, separate_out2 are used in prompt management. Eventually these things should be refactored and moved to the frontends, just not yet.

* Added a custom context menu to the RichIPythonWidget which allows saving plot as an images or SVG documents. * Expanded generic SVG functionality and refactored it into its own module.

Numerous fixes to ConsoleWidget editing region maintenence code. It now impossible (or at least very difficult :) to break the input region.

* Implemented "smart paste" for ConsoleWidget. Continuation prompts are now inserted automatically on paste. * Moved inappropriate public method out of ConsoleWidget's public interface

* Fixed bug where ConsoleWidget accepted non-ASCII characters on paste (and also rich text in 'rich' mode) * Minor cleanup to SVG payload handling.