chore(pubspec): Update the SDK constraint to the latest stable version (1.3)

Closes #884

Closes #899
feat(routing): allow routing to view html

Fixes #425

Closes #908
fix(application_factory): add missing @MirrorsUsed targets

A couple of types were missing for @MirrorsUsed when compiling with dart2js and using the dynamic
app.

Closes #911
chore(template_cache_generator): move options to flags with sensible defaults

Closes #916