AssetLoader: corrected Util import.
Util: added tcheck_obj() and last(); removed type-table support from tcheck().
Hooker: tidy; added missing typechecks.
Bind: tidy; added data.__initialized.
FieldAnimator: tidy.
Util: added debug(). Core: added f4 bind to toggle State.debug_mode.
Added AudioManager; added test sound.

Added module AudioManager.

AssetLoader: added sound support.

Asset:
    moved loading to Core;
    added test sound.

Core: added test sound trigger with hooklet.