`_root` is calculated dynamically based on the clip the currently executing function was called in.
Other things that used `context.root` have been changed to either update all layers or just update layer 0, which is the former `context.root`.
When a movie clip or button is used as a mask, the masking will be
disabled if that object has no children; the maskee will be
completely visible. An empty movie clip inside an empty movie clip
successfully masks.
An EditText can also not be used as a masker (although it can be
wrapped inside a movie clip, and then the text successfully masks).
Add a `TDisplayObject::allow_mask` trait method that will
return whether the object can be used as a mask.
This fixes characters not being visible in Dad 'n' Me.
Previously we set the name of the root clip to `_level0`. Top-level
clips should actually have no name (`_root._name` returns `""`).
However, when constructing a dot path, `_level0` still gets inserted
by `DisplayObject::path` for the top-level, so that `trace(_root)`
still correctly prints `_level0`.
TODO: When `loadMovieNum` gets merged in, the proper level # needs
to be returned by `.DisplayObject::path`.
Fire unload clip event when a movie clip is removed. Added
`ActionType` enum used by `ActionQueue::queue_actions` that
determines the type of action that is running (replaces `is_init`
parameter).
Add DisplayObject::slash_path to get the Flash 4-style slash path
to the clip. This fixes the tellTarget regression test and removes
the superfluous `target_path` from `UpdateContext`.
Note that host objects that do so will *not* have access to their standard representation from within member functions - you will need to extend the interface to accomodate for them. This is due to long-standing limitations with type IDs and downcasting with types that bear lifetimes - it's entirely an unsafe operation and exposing such a facility to safe Rust is unsound. However, this will at least let us separate out several things from ScriptObject that don't need to be there for the time being.