docs(tutorial/step9): formatted Unicode character line

Add tick and cross mark corresponding to their respective unicodes.
fix(jqLite): prepend array in correct order

Match jQuery behavior when prepending array into empty element
fix($compile): empty normalized href should pass sanitation check

Sometimes IE returns an empty string for its normalized href on a tags.
This should pass the sanitation check in $compile.

Closes #2219, #2593
docs(guide/directive): make directive controller minification-safe

It is best to emphasize that the "controller" property needs to be min safe

Closes #3125
docs(input): ng-model doesn't work well with isolated scope directive

Closes #3123
docs(guide/e2e-testing): fix typos
docs(numberFilter): fix explanation of default fraction size

The default fraction size for the number filter is actually computed
from the `NUMBER_FORMATS.PATTERNS.maxFrac` value in the current locale.

Closes #3157
docs(ngModelController): provide a more intuitive example

The example directive, using contenteditable was not showing required
even if you cleared the content from it.

Closes #3156