Started refactoring Leaf and Branch into a single Structure class
Reverted change to `values` and `indices` to be recursive for now, and updated remainder of code to follow refactoring into Structure.
Fixed name change back
Fixed bug in ``fill_footprint`` following refactoring.
Finished changing coords to indices and intensity to data_value
Fixed a key that was incorrectly changed in previous commit
Renamed components.py to structure.py
Added tests of Structure API
Added test for _add_pixel()
Reset cached values if pixels are added to a structure
Added more tests for Structure class
Merge pull request #17 from astrofrog/refactor

Minor change in API