Revert "feat(http): support coalescing http requests"

This reverts commit 1fb668b7f7154fd40a4112f2b24f455557ae740d.

Only reverting because g3 is not ready for it yet.
fix(cache): Make UnboundedCache extend Cache

Closes #1174
docs(developer): fix developer docs listing incorrect scripts to run for testing

DEVELOPER.md previously directed developers to run scrips/env.sh before running
tests, which is unnecessary and will cause their terminal to exit whenever
a command ends with a non-0 exit code.

Closes #1187
Closes #1188
docs(developer): fix typo in DEVELOPER.md

Closes #1210
fix(examples): do not use shadow DOM

This is in preparation for implementing the Testability API and Protractor
end-to-end tests since chromedriver can't handle shadowDom references.
fix(karma): remove saucelabs from default browser list.
chore(benchmark): Convert to DI bind syntax

This code was originally authored by @mhevery in the
DirectiveInjector change.
chore(cache): warnings

This code was originally authored by @mhevery in the
DirectiveInjector change.
chore(cd): Add a toString() method

This code was originally authored by @mhevery in the
DirectiveInjector change.
chore(parser): Remove unused 'annotationsFor' method from FormatterMap

This code was originally authored by @mhevery in the
DirectiveInjector change.
chore(NgModel): Fix a typo

This code was originally authored by @mhevery in the
DirectiveInjector change.
chore(git): Add perf as a valid commit message type

This code was originally authored by @mhevery in the
DirectiveInjector change.
chore(keys): Make DI Keys final

This code was originally authored by @mhevery in the
DirectiveInjector change.
perf(various): Avoid putIfAbsent

This code was originally authored by @mhevery in the
DirectiveInjector change.
perf(element binder): Do not create tasklists when not needed

This code was originally authored by @mhevery in the
DirectiveInjector change.
fix(transcluding component): Perfer getByKey over get

This code was originally authored by @mhevery in the
DirectiveInjector change.
fix(NgModel): Read the view value in the flush phase

This code was originally authored by @mhevery in the
DirectiveInjector change.
chore: remove noSuchMethod which improves dart2js size by about 100k
fix: incorrect mirrors import
perf: fewer string concatenations (10% improvement)