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
fix(introspection): fix ngProbe with introspected bindings and findElements returning only elements