docs(guide/accessibility): add sortOrder to get it in the right position in the guide
docs($compile): improve transclusion documentation

Closes #9352
test($compile): add test for alternative syntax to get controllers from ancestors

Because the regex that tests the `require` value will match more than just `^^?`,
it is important to test other common ways to specify a controller requirement
to ensure that a breaking change isn't introduced inadvertently. This adds a test
for `?^^`.

Closes #9389
Closes #9390
docs(CHANGELOG.md): update 1.2.26 release name
fix(form): fix submit prevention

Do not prevent submit when action
attribute equals to an empty string.

Closes #3370
Closes #3776
perf(ngBind): set textContent rather than using element.text()

"Speeds up chrome with ~10% firefox by ~5%"

We don't really see this result in benchmarks (https://www.dropbox.com/s/76wxqbvduade52s/big_table_benchmark_b1ee5396_vs_d580a954.zip?dl=0)
However, it's basically harmless.

Side effects:

Use strict equality check for `undefined` to replace with empty string. Most target browsers will output `undefined` rather than the empty
string if we don't do this. Previously, ngBindTemplate did not perform this check. However the change has been made to make behaviour
consistent across all target browsers (chrome does output the empty string).

Closes #9369
Closes #9396
fix($location): allow 0 in path() and hash()
chore(release): create script to undo a release for given number
fix(orderBy): sort by identity if no predicate is given

Closes #5847
Closes #4579
Closes #9403
docs(angular.element): `css()` method does not retrieve computed styles

The jQuery css() getter functionality utilises getComputedStyle() whereas
jqLite only retrieves what is declared inline on an element.

Closes #7599
fix($animate): clear the GCS cache even when no animation is detected

$animate will cache subsequent calls to GCS in the event that the element
with the same CSS classes and the same parentNode is being animated. Once the
animation is started then $animate waits for one rAF before flushing the GCS
lookup cache. Prior to this fix, if GCS was unable to detect any transitions
or keyframes on the element then it would simply close the animation, but it
would not trigger the rAF code to flush the cache. This issue caused a bug
which made it difficult to detect why certain animations are not allowed to
fire if the element didn't contain any CSS-based animations beforehand.

Closes #8813