adding ability to fill in null values with linearly interpolated values
adding null-interpolator
tests for null filling
moving into lib
moving to lib + renaming a few things for clarity
linear step smoothing incorporated
tweaking, adding min number of 5 before filling occurs
console.log was there but it wasnt - trying to fix
adding more better null handling
changed to 3-point limit (=== kernel size)
Merge pull request #60 from mapbox/async-fillnull

Async fill null values in query
Merge branch 'master' into async

Conflicts:
	index.js
	test/test.js
Merge branch 'async'