Make warn and print utility functions invoke the underlying functions with all arguments

Enables logging multiple values, including non-stringified objects in the browser.
Don't stringify objects in AVM1 warnings

Makes debugging quite a bit easier than "[object Object]" logs.
Streamline license headers on AVM1 stdlib files
Implement AVM1 support for BitmapData and MovieClip#attachBitmap
Fix child depth-related AS2MovieClip methods and make them native
Reformat BitmapData.ts

Horizontal scrolling in source code is almost as bad as vertical video.
Make void-returning BitmapData method stubs not throw

These transform the BitmapData's content, so obviously we want to implement them. No need to make them throw until we do, however.
Merge remote-tracking branch 'origin/nat' into nat

Conflicts:
	src/flash/display/BitmapData.ts
Merge pull request #1460 from tschneidereit/nat

AVM1 stdlib improvements