fix(angular_spec): export symbols for the route preLeave event
perf(view factory): Remove a try-catch and a timer for the critical path

This saves 4% (50ms) in the TreeComponent benchmark.
perf(view factory): Remove try-finally from ElementBinder._link

This saves 9% of the runtime in the TreeComponent benchmark.
perf(watch group): Do not use List.map for tiny lists
perf(view factory): Compute DI Keys ahead of time

4% improvement in TreeComponent benchmark

For #1081
benchmark working code: Do not use scope.watch for change detection.

Instead, roll our own "observable"-like system.
feat(benchmarks): Add benchmarks to folder
NgInternalOptions
Custom injector
scope watch wip