Tinkers' Steelworks

New
-Limestone has worldgen (followed by a simple on/off config setting) - it's generation will be heavily tweaked in coming releases. As of now, it typically generates under oceans and rivers (around the same areas you find sandstone), and occasionally around underground pools. As of now, it's mostly purely decorative, but will have many, many uses in the future.

Bugfix
-Thermal Expansion slag output
-OreDictionary sand (and coal?) entries caused incompatibilities with Ex Nihilo and presumably others
-Minor issues with the High Oven and Deep Tank structures not validating properly after a block is replaced
-High Oven scaling max temperature by structure height was a little weird