Revert "Merge pull request #7 from tobyk100/headers"

This reverts commit 1a36ca79fa9c9e40f15dfaa535effab25809d837, reversing
changes made to baa004af2afe4f040aeae71971c8bdbef503d426.
Revert "Guard against undefined headerGroup"

This reverts commit 8bedbf4487b7f86e332103a68ef1bd7182204edd.
Revert "Merge pull request #5 from tobyk100/headers"

This reverts commit c30e3c53223f735f6bfb0c4377e0069273bbb0b0, reversing
changes made to 27d44988de5c83629fd011c89333534fb72b4a51.

Conflicts:
	blockly_compressed.js
Added width getters for workspace and toolbox.
Abstract msie, trident test.
Build compressed.
Merge pull request #8 from tobyk100/headers

Headers