move base64 encoder/decoder into shim.js
rename defaults.fill to backgroundColor
remove unused code
Revert "build"

This reverts commit 6af74b2ba35460c58b88ce382e44ba16cffb351e.
Revert "build"

This reverts commit d82bee4640da63c21b8189beca00b7615384a5f1.

Conflicts:
	dist/contour.js
	dist/contour.min.js
	dist/contour.min.map
Revert "build"

This reverts commit d82bee4640da63c21b8189beca00b7615384a5f1.

Conflicts:
	dist/contour.js
	dist/contour.min.js
	dist/contour.min.map