Change window to global in the most outer IIFE parameters.

In the most outer IIFE it’s not yet known if the global is window or not.
Using the window variable to denote the global was misleading in that case,
especially that the code didn’t make such assumption, requiring to provide
a Web-like window separately. Renaming window to global clears the confusion.
Effects: Integrate sinon fake timers into tests. Close gh-1377.
Add unit tests for .html( number ). Close gh-1447.
Ajax: Use weak ETag header in tests

See http://en.wikipedia.org/wiki/HTTP_ETag#Strong_and_weak_validation

Close gh-1448
Fix #14579: attribute selectors with trailing spaces after an unquoted value