notebookapp: add missing whitespace to warnings
add IPython.get_ipython

library entry point for get_ipython

does not rely on injection into globals
Don't rely on `get_ipython` in builtins in library code
don't use deprecated ipapi.get

It's been deprecated for three releases.  Come on guys.
remove reference to nonexistent 0.14 in deprecation warning
move core.ipapi -> core.getipython
remove deprecated `get`
rename `%%file` to `%%fwrite`

keeps `%%file` as alias

Alternative to #3313, no behavior is changed.
make that writefile
Moving handlers to subdir
Adding new files.
Splitting handlers into different files.

I have also created a top-level utils.py for notebook related stuff
Adding __init__.py
Fixing url join problems.
Removing debug message.
define `__file__` in config files
More work on the handlers
Reorganizaing the server side of the notebook.
Updating import statements after moving notebook files around.
Renaming api handlers and moving FileFindHandler into base handlr.