Move interface decl to better loc
Initial implementation of smoothing
Rename bin_vector to vector_bin. Closes #1
Document vector_smooth
Use full argument name
Copy over bin_param from ggvis
Copy over vector_bin() tests from ggvis
Minor bin param cleanup
Import & re-export %>%
Add R wrapper for frange
Test frange with different vectors
Improve frange documentation
Port bin param tests from ggvis
Refactoring bin_params