Fix order in which frame scripts are invoked
Merge pull request #1480 from tschneidereit/nat

Fix order in which frame scripts are invoked
Propagate MovieClip's frame script pending-info upon being added to the stage

Also abstracts the operation of setting a parent and consistently applies `add/removeReference`.

Fixes the situation where a frame script is added to a MovieClip before it is added to the stage, and then the play head doesn't move, so nobody ever knew about the script.
Merge pull request #1481 from tschneidereit/nat

Propagate MovieClip's frame script pending-info upon being added to the stage
Merge pull request #1482 from mbebenita/avx

Cleaning up build system.
Fix file reference, type-o.
Merge branch 'nat' of https://github.com/mozilla/shumway into avx