Obey more DT config, make config option to override with TFC defaultish values

[Gaelmare]

Since most players don't bother reading and expect out-of-the-box config to work, should add a config file/have a config option to alter DT defaults to match TFC as described on CF page/TFC #tng-addons channel.

Also I guess it should obey DT config file to disable treegen if players decide to stop using DTTFC in the middle of a game. Look into what that config option does besides disable treegen, sapling spawns?