fix flaky test

Fix flaky tests that timeout by removing dynamic module dependencies in
favor of cached module dependencies.
Mock Y.Lang.now for predictable throttle tests. Fixes #803
Merge branch 'master' into dev-master

Merging master back into dev-master due to an inadvertent push after a rebase.

This introduced duplicate commits with different SHAs in both branches. The
duplicated commits have the commit message "fix flaky test" and have the SHAs
3b1b3027c104847a4bb2b166eade8ea083c77b1b (master) and
3568d7d6fd111dc5e0ce5b43ea1cd8b63a55c8df (dev-master).

As part of the rebase, the following commits should get reintroduced into
master with this merge.
1d4a48de92952ffdeb7cbc240dc91d8074f4df99
641f056f18c8da90fad015c5e5f0f983c9abbd89
128072c368c0f7cca8856cdea6bd32eee0467531
YUI and Loader build for latest Gallery build
Took out arbitrary 200ms timeout. With the default poll interval at 50ms, IE had the potential to timeout before polling happened
Refactored tests to avoid explicit timeout waits where possible, and stop polling on teardown.

Moved the rest of the tests to a separate test case, and bumped up the timeouts,
even more so for IE, which has been flaky.

I believe the issue was that in some cases (with a 200ms explicit timeout) we were timing
out before the 50ms polling time came around on sluggish machines/browsers.
Added window.focus call to help with IE8 flakyness.

If the window lost focus, IE8 (like the know issue with FF) would fail
focus/blur based tests.
Merge branch 'event-valuechange-test-robustness' into dev-master