docs: fix the "show source" button

Closes #4904
chore(release): cut the 1.2.1 underscore-empathy release
chore(release): start a new release iteration
chore(*): remove accidentally created file

Closes #4963
docs(guide/i18n): fix link to i18n files in the project

Closes #4998
docs(tutorial/step-4): controllers are no longer global functions

The docs did not line up with the codebase / previous steps of the tutorial.

Closes #4988
docs(guide/directive): add note about HTML case-insensitivity

Closes #4719
docs(guide/directive): clarify code example for isolated scopes bindings

Use different names for the attribute on the element (`info`) and the property (`customerInfo`)
on the isolate scope. Before `customer` was used for both which made it harder to understand.

Closes #4825
docs(ngApp): improve description and example
chore(travis): increase disconnect timeout

I still see some disconnection issues with IE9, hopefully this will help a bit.
docs($animate): update the docs explaining enable/disable for specific elements
docs(guide/migration): fix typo

Closes #4965
docs(tutorial): minimum node.js version is 0.10 (Windows too)

The doc has been modified by the following commit: bcc6e8d4f64a18039e0ed2eee0b54c17471b43e3
But the change was not made ​​for the part of Windows.

Closes #4967
docs(ngRoute): make it easier to find the example

Closes #4975
docs(api): example for $provide.value() uses $provide.value()

The example code for `$provide.value()` actually used `$provide.constant()`.
It now uses `$provide.value()`.

Closes #4983
Closes #4990
docs(guide/compiler): fix typo in isolate scope def

Closes #4999
docs(guide/migration): fix typo

Closes #5002
docs(guide/providers): remove extra closing parenthesis in example

Closes #5005
docs(guide/ie): fix typo

Closes #5006
docs(guide/directive): use `hideDialog` handler in example

The handler is in the controller but was not being used in the template.

Closes #5020