CLIMATE-411 - Add overview section to sphinx docs
CLIMATE-554 - Switch sphinx metrics page to autodoc
Resolve CLIMATE-411. Merge PR #134.
Resolve CLIMATE-554. Merge PR #135.
CLIMATE-555 - Update sphinx doc version

- Update version number to 0.4-snapshot.
- Fix really really old copyright that was never changed after initial
  testing.
Resolve CLIMATE-555. Merge PR #136.
Fix typo in toolkit example
Fix bad indent in dataset_processor docstring
CLIMATE-372 - Add custom names to local data source
CLIMATE-372 - Testing local custom dataset name test
CLIMATE-372 - Add custom names to dap data source
CLIMATE-372 - Testing dap custom dataset name test
CLIMATE-372 - Add custom naming to esgf data source
CLIMATE-372 - Add custom naming to RCMED data source
CLIMATE-372 - Testing custom RCMED dataset naming
CLIMATE-558 - Add config for external doc linking

- Add necessary configuration for linking to numpy, scipy, and
  matplotlib documentation.
CLIMATE-558 - Update dataset module documentation links
CLIMATE-558 - Update dataset_processor module documentation links
CLIMATE-558 - Update Evaluation module documentation links
CLIMATE-558 - Update metrics module documentation links