Add script to help with testing interactive examples.

Small script I've been using to help test examples that require human interaction.  It opens each file in a given examples directory, waits for user input before opening the next example to see if things had displayed correctly, then logs any errors to a log file.
This script seems customize to be used in plotting subfolder, but you now have a lot of more examples at the examples directory (mpl, seaborn, ggplot, pandas, etc)... Maybe you can do it more generic...