WTF's Expedition: CaveBiomes, Ores, Trees, and Tweaks

Added config option to change maximum generation buffer size- users with performance issues may find tweaking this helps.

Removed gameplay config optiosn from expedition- as the gameplay tweaks are now a seperate mod, it's no longer needed.

Minor performance tweak to gen buffering.

Fixed config option on the sandstone replacer- turning this off will now disable sandstone replacement.