Update notebooks

[bgrant]

For all notebooks: rerun and save in the new notebook format (v4 I think). Closes #601.

For features.ipynb:

1. Print out the versions of packages used.
2. Use a seeded RandomState instance at the top, so the notebook doesn't have random changes from run-to-run. Closes Use a RandomState at the top of features.ipynb to avoid unnecessary notebook versioning #612.

For ge_notebook.ipynb:

1. Fix a failing call to %timeit, due to a bug in the current version of IPython.