Revert "Remove a bunch of stuff + update to support modlauncher"

This reverts commit 6b59f9c

src/main/java/net/fabricmc/loom/LoomGradleExtension.java

@@ -33,6 +33,7 @@ public class LoomGradleExtension {
 	public String runDir = "run";
 	public String omlVersion;
 	public String pomfVersion;
+	public String refmapName;
 	public boolean skipPrebake = false;
 	public boolean localMappings = false;