chore(changelog): update changelog to alpha.42

chore(changelog): update changelog to alpha.41

chore(changelog): update change log to alpha-40

chore(changelog): update change log to alpha.39

chore(package): bump version to alpha 38

chore(changelog): update change log to alpha 37

chore(changelog): update change log to alpha 36

fix(docs): export bootstrap in core.ts but not in core.dart

test(router): add tests for router.d.ts

Closes angular#3282

refactor(ElementBinderBuilder): remove unused code

Closes angular#3326