Small css changes
Reorganized imports

- Exposes core API components and simplifies their import
- Avoids previous dependency problems
Moved standalone scripts

- Decouple standalone scripts from analysis class files, to simplify
maintenance
- Emphasizes standalone scripts as examples, and helps show how users
can create their own, rather than provide exhaustive functionality
Change error text
Moved key-related methods to a separate module
Clean-up
Expanded documentation with notebook tutorials

- Use iPython notebooks for tutorials, convert to rat when building
documentation using Sphinx
- Inspired by the tutorial framework used by the seaborn library
Minimize py4j output during tests
Significant refactoring of new data types

- Modify analysis routines to assume Series (or subclass) input
- Support lazy transfer of attributes across different data types, so
that dimensions and indices are computed once and maintained
- Simplified constructor interface enables easy extension for new data
types
- Added TimeSeries and SpatialSeries types, with time or space specific
methods