New ZNotebookCanvas for IPython work

Details:

--Folding in the 'RIPN' (ROOT IPython Notebook) classes to this
  repository. Completely rewrote the ZNotebookCanvas class. It is now
  vastly more powerful, more robust, and streamlined.

--Minor updates to the README file
Merge branch 'master' of https://github.com/zach-hartwig/ROOTUtilities