Add Venq.vtk
Update VTK notebook
Fix TVTK notebook
Update the VTK one
Update commit plots

I didn't change all references to "mpl" to "matplotlib" in the notebook.

Also:

- Remove django
- Add scipy and pandas
- Remove the normalized plot
- Add an all time plot
- Add bullet points
- Add a dashed line to the year plot
Uncomment bullet point
Rework FFT intro
Charged sphere
Use SymPy to derive the charge density
Update slides

Update plots with latest SymPy data, and add list of authors
Add more stuff
Put the features on two slides

Reindent the LaTeX file
Update matrices file
Merge branch 'master' of github.com:certik/scipy-2013-tutorial
Update slides
Merge branch 'master' of github.com:certik/scipy-2013-tutorial
Typo
Add links to slides and source
Use words for the links
Update outline and add welcome page