BUG: ExtensionContainer::removeAllExtensions() crash

In revision 11320, see lines 69-76. Line 73 attempts to access non-existent method.

EXISTING:

 public function removeAllExtensions( ns:String ):void
    {
        for (var i:String in _exts[ns])
        {
           ** _exts[ns][i].ns();**
        }
        _exts[ns] = [];
    }

PROPOSED:

 public function removeAllExtensions( ns:String ):void
    {
        for (var i:String in _exts[ns])
        {
            removeExtension(_exts[ns][i]);
        }
        _exts[ns] = [];
    }

Note: This method is only referenced from a single location in XIFF: Message.as::set htmlBody (line 311)

Applied in revision 11544.

Thank you