refactor(layout.layoutManager) Cleaned up code a bit in setLayout(). Commented out rediculous test.
refactor(d3-ext) Changed layout elem classname since its scope broadened.
fix(layout.layouts) Fixed top double-border bug.
feat(d3-ext.clip) Added clip() extenison. Optionally gets applied by layout manager.
Merge pull request #71 from racker/clip-path

Add clipPath to prevent bleeding.