Closes #16857

…& v1.7.x

Closes #16862

This updates jQuery to 3.4.0 to ensure future security fixes won't break it.

Closes #16863

Since d6098ee, old styles were not removed if `newStyles` specified an
invalid value for the style (e.g. `false`). The assumption was that the
new style would overwrite the old style value, but using an invalid
value made browsers ignore the new value and thus keep the old style.
This would typically happen when guarding a style with a boolean flag;
e.g.: `ng-style="{backgroundColor: isError && 'red'}"`

This commit essentially revers commit d6098ee, whose main purpose was
to work around jquery/jquery#4185. The jQuery issue has been fixed in
3.4.0, so that should not be a problem any more.

Fixes #16860

Closes #16868

Closes #16876

The currently latest-1 version of desktop Safari (v12.0) on SauceLabs is
completely unstable. Switching to the latest version (currently v12.1),
which works fine.

Closes #16888

By blocking `__proto__` on deep merging, this commit
prevents the `Object` prototype from being polluted.

(cherry picked from commit 1147f0e)