better type and dimension checking for indices in structure_at
Merge pull request #98 from keflavich/structure_at_indexing

Minor change: check type of index before using it
Multiple Selections and Scatter plot visualization
Documentation for dendrogram scatter
Rename DendroScatter to Scatter, extract plt.show into separate viewer method
Make sure full dendrogram is plotted in the back
Prevent mouse wheel events from raising exceptions
Tweak scatter documentation
Merge pull request #105 from ChrisBeaumont/scatter

Multiple Selections and Scatterplots
Custom adjacency logic for periodic data
Move snippet to comment
Proper keyword passing
Merge pull request #108 from ChrisBeaumont/master

Custom adjacency logic
Reload bugfix. Closes #106
Merge pull request #110 from ChrisBeaumont/106

Reload bugfix