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
Merge branch 'dev-master' into dev-3.x

Updated dev-3.x with latest dev-master.
YUI and Loader build for latest Gallery build
Merge branch 'dev-master' into dev-3.x

Update dev-3.x with latest dev-master for latest gallery build.
Merge remote-tracking branch 'upstream/dev-3.x' into dev-3.x