style: Rename variables of the form $name into name .

Closes #854
fix(cookies): Make sure Cookies is injectable.

Also clean-up a few warnings and remove an unnecessary workaround
in the todo example.

Closes #856
feat(Scope): Allow turning emission of scope stats from console.

To enable emission of ScopeStats from console one can call function `enableScopeStats(Node)`. To disable call function `disableScopeStats(node)`.

Fixes #836

Closes #857
docs: Correct double import of annotations for documentation.
fix: dart2js build size checks relaxed