Enable pregenerated (for Dart) and JIT (for Js) change detectors when
possible. Previously we would always use `DynamicChangeDetector`s, but
these cause megamorphic calls and are therefore much slower.
Closes#502
But do it during the build process for cjs.
Right now we only need this when we transpile from ts
directly to es5. This is only the case in our
cis build, as for our browser build we only transpile
from ts to es6 via ts and then use traceur to do
the rest.
Also consolidates metadata handling in `ElementInjector`
BREAKING CHANGE:
- renames `DirectiveMetadataReader` into `DirectiveResolver`
and removes `src/core/compiler/directive_metadata`.
Fixes#1712Fixes#1713
