Disabled Railcraft ore spawns

Disabled the copper, gold, iron, saltpeter,  sulfur, and tin spawns from
Railcraft. These are replaced by GregTech spawns. The other ores are not
used by GregTech, so they're cool.
Revert "Disabled Railcraft ore spawns"

This reverts commit 93676038e0213ccf30b5ba8c5c1ac7c47b8bb37e.
Revert "Revert "Disabled Railcraft ore spawns""

This reverts commit 296ce106e841ce60819cf3099db4c7de16c0d0e3.
Major mod update (with slight console revisions)

Updated all the mods (Forestry is using an older version for now). I've
also tweaked the configs a little just to specialise Greg a bit. Now I
just need to play it for a while.
Re-enabled vanilla ores

After playing around, having so much trouble getting iron, I've decided
to put the vanilla ores back into the world generation.
Readme change, ready for the A03 push

The readme has been edited so that it's ready for the A03 push today.
Merge pull request #4 from Biendeo/testing

Merge testing to the master branch for the A03 update.