feat(scope): add new createProtoChild method

Internalizes PrototypeMap, and allows for easier switch to ContextLocals.
feat(compiler): support ScopeAware for decorators

Even though decorators can safely inject scope (even after the proposed
context change), they might pick up ScopeAware from a base class shared
with components. Instead of manually calling super.scope = scope, we
support ScopeAware for decorators (similarly to Attach/DetachAware.)

There is no performance reduction on the tree benchmark.
refactor(NgElement): NgElement inject RootScope instead of Scope.

NgElement only uses scope to access rootScope, so now we directly inject
RootScope.

This is needed for future change #1429 which disallows Scope injection
into controllers. Since NgElement depends on scope it would also be
disallowed, unless we change it to directly use RootScope.
Revert "feat(compiler): support ScopeAware for decorators"

This reverts commit 9659dd1721c8011bd26d1855ca268a967805c4e2.

Wrong version of this PR was added in master, correct version is in
g3v1x.
feat(compiler): support ScopeAware for decorators

Even though decorators can safely inject scope (even after the proposed
context change), they might pick up ScopeAware from a base class shared
with components. Instead of manually calling super.scope = scope, we
support ScopeAware for decorators (similarly to Attach/DetachAware.)

There is no performance reduction on the tree benchmark.
chore(introspection): clean up workarounds for dart 1.4 and 1.5
fix(scope): fix a potential memory leak
perf(view): increase view instantiation speed 40%

1) Stop using futures when the value is already cached
2) Remove adding nodes to fake parent during view instantiation

Closes #1358
feat(core, testability): PendingAsync service

A new PendingAsync service that is used to track pending async
operations in Angular.  VmTurnZone ties in to this service to track
timers as async tasks and correctly handles canceled timers.  Http
registers async tasks for network requests.  The Testability API uses
the new API to provide a much more useful whenStable implementation.