Remove superfluous window scoping
Move compositor out of DEFAULT_GROUP to global scope

There's no particualr reason why the compositor should be part of
DEFAULT_GROUP, and DEFAULT_GROUP will be going away with the upcoming
refactoring for TimeSources, so move it now.
Fix test-svg-anim.html
More style fixes
Merge pull request #61 from steveblock/style

More clean-up in preparation for TimeSources
Merge pull request #58 from dstockwell/text-content

Use textContent instead of innerText
Be more precise when parsing lengths
wip
support unitless lengths?