docs(guide/understanding_controller): fix incorrect property reference

Correct " model property `spice` " to " model property `customSpice` " to match the code sample

Closes #4812
docs(guide): fix typo

Closes #4821
docs(errors/compile/tplrt): display html block as code

HTML elements were getting parsed by as HTML elements

Closes #4827
docs($httpBackendSpec): fix typo in spy name

Closes #4830
docs(contribute): justify note about elevation on Windows

This message needs a justification. Without one, it's like asking somebody
on *nix to run everything under sudo 'just because'.

Closes #4832
docs(guide/scope): ensure demo CSS styles work in JSFiddle and Plunker

The CSS styling in the ng-scope demo was using CSS classes (`.doc-example-live` and
`.show-scope') to prevent the styling for the demo from affecting the entire page.
Unfortunately elements containing these classes did not appear in JSFiddle or Plunker
when you click edit.

This fix moves the `.show-scope' class inside the demo (renaming it `.show-scope-demo`)
and removes the reliance on `.doc-example-live` altogether.

Closes #4838
docs(guide/scope): correct scopes example

Remove reference to `employee` property as it's not used in the example.
Inject and use `$rootScope` applying `department` property as mentioned in text.

Closes #4839
Merge branch 'master' of https://github.com/angular/angular.js