motherlode.ucar server has been deprecated, replaced with thredds.ucar
Refactoring subsetting logic.
Improved temporal subsetting.

Added tests for slicers.

Handful of bugs in tinylib/windbreaker
Subsetting no longer requires that the first forecast time
be the reference time.
extract_domain_grid is no longer used.
Improved docs.
Merge pull request #10 from akleeman/route-forecast-xray

Cleaning up forecast fetching logic.