add RF API and add concept of energy usage to machines + controllers

src/main/java/cofh/api/energy/IEnergyHandler.java

@@ -0,0 +1,58 @@
+package cofh.api.energy;
+
+import net.minecraftforge.common.util.ForgeDirection;
+
+/**
+ * Implement this interface on Tile Entities which should handle energy, generally storing it in one or more internal {@link IEnergyStorage} objects.
+ * <p>
+ * A reference implementation is provided {@link TileEnergyHandler}.
+ *
+ * @author King Lemming
+ *
+ */
+public interface IEnergyHandler extends IEnergyProvider, IEnergyReceiver {
+
+	// merely a convenience interface (remove these methods in 1.8; provided here for back-compat via compiler doing things)
+
+	/**
+	 * Add energy to an IEnergyReceiver, internal distribution is left entirely to the IEnergyReceiver.
+	 *
+	 * @param from
+	 *            Orientation the energy is received from.
+	 * @param maxReceive
+	 *            Maximum amount of energy to receive.
+	 * @param simulate
+	 *            If TRUE, the charge will only be simulated.
+	 * @return Amount of energy that was (or would have been, if simulated) received.
+	 */
+	@Override
+	int receiveEnergy(ForgeDirection from, int maxReceive, boolean simulate);
+
+	/**
+	 * Remove energy from an IEnergyProvider, internal distribution is left entirely to the IEnergyProvider.
+	 *
+	 * @param from
+	 *            Orientation the energy is extracted from.
+	 * @param maxExtract
+	 *            Maximum amount of energy to extract.
+	 * @param simulate
+	 *            If TRUE, the extraction will only be simulated.
+	 * @return Amount of energy that was (or would have been, if simulated) extracted.
+	 */
+	@Override
+	int extractEnergy(ForgeDirection from, int maxExtract, boolean simulate);
+
+
+	/**
+	 * Returns the amount of energy currently stored.
+	 */
+	@Override
+	int getEnergyStored(ForgeDirection from);
+
+	/**
+	 * Returns the maximum amount of energy that can be stored.
+	 */
+	@Override
+	int getMaxEnergyStored(ForgeDirection from);
+
+}