Align HTMLAppletElement IDL with spec

• Component: Plug-ins
• Status: RESOLVED WONTFIX

[Ryosuke Niwa]

Consider merging https://chromium.googlesource.com/chromium/blink/+/cd68b8af13f894be2a69b0a886781d8f8d7cb17f

http://whatwg.org/html#htmlappletelement

In addition to removing TreatNullAs=NullString, align with the spec by
making hspace/vspace unsigned long, and codebase/object URLs.

The tests for the updated properties pass in Firefox Nightly, IE11
Release Preview and Opera 12.16, with these exceptions:

IE11 returns "" after setting width/height to null and fails all of
the vspace/hspace reflection tests in ways not per spec.

Presto doesn't reflect object as a URL, but the framework didn't
notice that before the minor fix in nullTestElementAttribute.
Presto also fails the vspace/hspace set tests in ways not per spec.

[Alexey Proskuryakov]

Mass closing plug-in bugs, as plug-in support has been removed from WebKit.

Please comment and/or reopen if this still affects WebKit in some way.