Oregen correction pass Part 2

The heightmap has been revised to reflect the changes in Parts 1 and 2.

Corrections:

* Mithril no longer clashes with other materials and has been reactivated
* Aluminium is now handled by Tinker's Construct as Mariculture is unreliable
* Miscellaneous mods not obeying the heightmap have been spotted and corrected

RR3 revisions and upgrades:

* TiCo bushes are bandshifted ten blocks above their counterpart ores when possible
* Lead has been moved much closer to the surface than in RR2
* Zinc oregen has been transferred back to Metallurgy
* Zinc oregen has been reconfigured to accomodate Flaxbeard's Steam