The older tree is inserted into <shadow>, and the original branch is inserted into <content>.
Added abort-after-timeout test.
Fixed a typo in abort-after-receive.
Fixed title.
Added an assertion that timeout actually happens.
Merge pull request #159 from Hiroyou/submissions/hiroyou-2

The older tree is inserted into <shadow>
Added an assertion to see if timeout is a supported feature to begin with.
Merge pull request #161 from ronkorving/submissions/ronkorving

Test that XHR abort() should not fire an "abort" event after a timeout happens. (reviewed by annevk)