Small fixes and cleanups
Merge pull request #1442 from mbebenita/nat

Fix bugs related to playing frames before they are loaded.
Remove optional arguments usage in AVM1 interpreter

We can easily guarantee that all callsites do the right thing here, and optional arguments have a runtime overhead.
Warn whenever AVM1 just swallows an invalid operation

We used to, incorrectly, throw errors on these operations. Flash doesn't, so we don't, anymore. At least, we should warn to aid our own debugging, if nothing else.
Change AVM1 ActionNewObject to ignore non-function targets

As per spec and Flash's behavior, not sanity.
Change AVM1 enumeration to ignore undefined targets

As per spec and Flash's behavior, not sanity.
Merge pull request #1443 from tschneidereit/nat

Warn instead of throwing on more AVM1 actions
Fix AVM1 checks for function callability/constructability

Some callable objects aren't `instanceof Function`, and some that aren't `typeof === 'function'` are still constructible.
Compiled avm1lib.abc with previous changes included
Merge pull request #1444 from tschneidereit/nat

Fix regression in constructing AVM2 classes in the AVM1 interpreter
Optimize handling of DisplayObjects that have to get notfied when a frame advances
Merge branch 'nat' of github.com:mozilla/shumway into nat
Merge pull request #1446 from mbebenita/nat

Stub NativeMenuItem
Fix check for `localStorage` support to not throw in Workers
Only try pushing the final tag in a SWF if the tag object exists
Merge pull request #1447 from tschneidereit/nat

SWF parser fixes
Merge branch 'nat' of github.com:mozilla/shumway into nat
Set fill and line styles from symbol
Fixed compiler error by linking and importing Shumway.SWF.Stream
Merge pull request #1445 from tobytailor/nat

Misc optimizations and cleanups