stack.
Move stacking to metadata and don't modify data.
Merge branch 'develop' into metadata_stacking

Conflicts:
	plottable.js
Merge branch 'develop' into metadata_stacking

Conflicts:
	plottable.js
Formatting.
Merge branch 'develop' into metadata_stacking
Add test.
Merge branch 'develop' into metadata_stacking

Conflicts:
	plottable.js
	test/tests.js
Merge pull request #1354 from palantir/metadata_stacking

Move stacking to metadata and don't modify data.