feat(change_detection): add benchmarks
fix(reflection): fix a typo
fix(reflection): update pubspec.yaml to add a missing dependency on reflection
refactor(benchmarks): rename paths.js into register_system.js to match other benchmarks
fix(benchmarks): add the reflection module to benchmark config files
chore: use load-plugins to make gulpfile shorter
fix(ChangeDetector): fix issues with handling empty ranges
refactor(change_detection): make RecordRange responsible for removing iself
feat(viewPort): adds initial implementation of ViewPort.

ViewPort is the mechanism backing @Template directives. Those
directives can use the viewport to dynamically create, attach and
detach views.
wip: integration test for template directives.