Logger constructor
Constructs a Logger instance.
The Logger is constructed with the SamHot of _sm as the data pool, _logKey as SamHots sym and with
a size of (_wid,_hgt); Optionally the background color can be set to color;
Implementation
Logger(this._sm,this._logKey,this._wid,this._hgt,{Key key,this.color = Colors.limeAccent}) : super(key:key);