Cleanup log4net string appender & enhance configuration

Log4net string appender now will not create a useless object with the type name.  It simply will just log a string thus keeping the stackify log console clean (easier to read).

Environment variable can now be use to configure settings instead of just .NET app.config or web.config files only.  This makes it easier to deploy to production VM snapshots with all the settings already burn into a blank golden image.  This new setting mechanism will first try to read from local web or app config file, if the key is not found, it will fall back to environment variable (user first, then global).

Console test is also updated to include the new change.