Bringing in changes April-June 2014

*   Simplified Makefile and added documentation.
*   New and improved Windows installer.
*   Updated ggplot2 example.
*   Renamed the `aux` directory to `misc` (since `aux` conflicts with Windows filesystem conventions).
*   Added image files produced from IPython Notebooks.
*   Added climate data example as wrap-up to Python lessons.    
*   Added links to how-to videos for instructors.
*   Added lesson on `doit`.
*   Added lesson on multiprocessing in Python.
*   Added `bin/swc_index_validator.py` to check formatting of bootcamp home pages.
*   Put rules for compiling IPython Notebooks into separate `ipynb.mk` Makefile.
*   Created `bin/setup-bootcamp.sh` to create and fill a bootcamp repository.    
*   Removing deprecated lesson material.
*   Many small changes to lessons, glossary, formatting, etc.