Upgrade to latest vector_math release
Merge branch 'master' of https://github.com/dart-lang/dart-box2d

Conflicts:
	example/benchmarks/benchmark_runner.dart
	lib/box2d.dart
	lib/src/collision/broadphase/dynamic_tree.dart
Whitespace
Merge pull request #30 from johnmccutchan/master

Upgrade to latest vector_math release