Engine rewrite

Killed Engine class, merged into TileEngine and subclasses.
Converted to Forge rotation API.
Split heat from stored energy and set proper temp bounds.
Rewrote IronEngineCoolant API, changed to degree based temp reductions
(its 0.0025 times the previous values). Added support for solid coolants
(they have to melt into a liquid coolant, like Ice to Water).
There is a commented out alternative implementation for constant power
output instead of pulsed.