feat(template_cache_generator): Support relative urls.
Merge remote-tracking branch 'upstream/master' into RelativeTemplateCacheGenerator
fix(docs): correct typo
chore(contributing): added contributing instructions.
chore(contributing): fix typo
docs(Scope): complete missing documentation for scope methods/properties

Closes #287
chore(test): fix analyze casting issues on ng_model_spec.dart
feat(forms): provide support for controls and state flags
feat(forms): add support for validation handling for multiple error types
feat(forms): provide support for parent form communication
feat(ngModel): provide support for custom validation handlers
feat(core): provide support to define the same selector on multiple directives
chore(docs): add docs for NgForm, NgModel and each of the NgModel validators
docs(readme): add @AngularDart and travis badge
chore(todo demo): Update the directory structure to be compatible with 'pub serve'
feat(js size): Add a default @MirrorsUsed to Angular.

Closes #409, #237
docs(mirrors): Update comments about MirrorsUsed
Switch to new generator
feat(helloworld): MirrorsUsed
Switched to DI generator instead of SourceCrawler from Angular.