docs(guide/directive): we are registering directives, not controllers

Closes #4615
docs(http): add missing brace in the 2nd interceptors example

Closes #4621
docs(Angular.js): angular.equals calls itself recursively on objects

Closes #4622
docs(guide/directive): improve wording
docs($q): promises are no longer automatically unwrapped, by default

Although it is still possible to turn this on, the feature is deprecated and it is
best to remove this mention completely here.

Closes #4632
docs(tutorial/step-11): add missing dependencies

Closes #4633
docs(guide/understanding_controller): apply a more intuitive metaphor

The BabyCtrl was a bit confusing and GrandChildCtrl seems to make more sense
with the whole "scope inheritance" concept.

Closes #4634
docs(guide/overview): improve grammar and readability

Closes #4639
docs(guide/directive): correct reference to myDir rather than ngBind

Closes #4647
docs(api/index): improve grammar

Closes #4648
docs(guide/e2e-testing): add note about Protractor replacement

Add a note to warn people starting new projects about Protractor replacing the
current ngScenario way of doing E2E testing.

Closes #4644