WHATWG HTML Cherry picks update 5/22/2014

Hello public-html,

Here are the latest WHATWG changes applied to HTML5.1 Nightly for your review. The W3C spec is in sync with WHATWG as of 2014-5-22 (SVN 8648).

Please reply back with any comments.

Thank you,
Erika

===Substantive changes=====
    [e] (0) Adjust examples in <iframe> section to increase diversity (8636)
https://github.com/w3c/html/commit/98913d8a70c065b0c2ebcba82c0d052a6f102762
    [e] (0) for compat, apparently alert() should alert '' and alert(undefined) should alert 'undefined'
    Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=25686 (8638)
https://github.com/w3c/html/commit/b828cf4ce1641e3240955adc69f5beb290a05a13
    [giow] (3) Looks like browsers make animated image groups follow the timeline of the first image, not last image.
    Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=25739 (8639)
https://github.com/w3c/html/commit/304e4ccab76d44d15c833020f8c1d647ff5e5ab3
    [e] (0) Various HTMLAllCollection fixes
    Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=25817 (8645)
https://github.com/w3c/html/commit/9e3b8b089b5341f05560660b665835c9c6ebb0d7
    [e] (0) Minor tweaks to the wording of the authoring section for autofill (8646)
https://github.com/w3c/html/commit/265ddbe50f8a58b5d8a0dcf136d7d3f5d2cfbac3
    [giow] (1) autofill: requestAutocomplete() should not need the form in a Document; section-* should be opaque. (8648)
https://github.com/w3c/html/commit/19b055c94c9a38da2fd617c4be7bfc32c9e76c65

===Editorial changes=====
    [t] (1) rel=external is more an annotation than a hyperlink (not published in W3C source)
    Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=25688 (8635)
https://github.com/w3c/html/commit/9e5791129ddd1b1bf24988151fe8038c049836ed
    [e] (0) Typo in canvas section
    Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=25672 (8637)
https://github.com/w3c/html/commit/2d76531526919972015f2df7717d1cead26a1467
    [e] (0) Reorder the list of DOCTYPEs to have the exact comparisons before the prefix comparisons, and remove commented-out values since there's very little chance of us having to change this again now that we have multiple deployed implementations. (8642)
https://github.com/w3c/html/commit/d3504b2e9afdcc946cf06c7b2911c5400be6be6b
    [e] (0) markup typo in Path2D section (8643)
https://github.com/w3c/html/commit/efe04cbc6aee335f1d57d85d798290ce98140f20
    [e] (0) More typos found by IZh (8644)
https://github.com/w3c/html/commit/55f7adcf1f469c0735bb386575a8d2ea5da1e18a
    [e] (0) Update reference for pagevis (8647)
https://github.com/w3c/html/commit/7cf33439d496db51008c1161d54222b398207fcb