Added CFD Python files
Updates for numerical-mooc

    * Deleted and changed references to CFD Python
    * Added license
    * Changed style
    * Changed imports to agreed convention
Trivial missing full stops.

Some semicolons to suppress output near plots.
Changed more references to CFD Python
Added solutions to spacetime module
Merge branch 'master' into spacetime_solution (update stylesheet)
replace all 26314 with eqn envir. to enable numbering
Merge pull request #8 from numerical-mooc/spacetime_solution_add_eqn_numbers

replace all $$ with eqn envir. to enable numbering
Changes to 1D linear convection notebook

    * Changed copyright information
    * Added welcome message to link to course
    * Removed links to youtube videos of CFD course
Edits on spacetime module

    * Modified copyright on all notebooks
    * Added welcome message linking the notebooks to the course
    * Deleted some leftover references to CFD Python
Python 3 compatible.

Also a minor typo.
Document the functions.
Python 3 compatible.

Minor additions to say what's going on.
Edits on spacetime_solution

    * Added discussion on numerical diffusion on notebook 1
    * Edits on first reference to stability in notebook 3
    * Added paragraph on stability for diffusion equation
Add description of time vs. spatial indices

Also remove some redundant intro material that was covered in the
Phugoid module.
remove 'extra' comments and explanations (already covered)
change 'intro of' to 'intro to'
remove old comments and "complete the code" section

add JSAnimation (not married to this, just an idea) to show behavior of
nonlinear wave over time.  might be tricky to explain how JSanimation
works, and how to install it, so maybe just an animated gif?
repush with output cleared
improve explanation of time vs spatial pos and add stencil