[configuration] added facilities to override conf file resolution for test cases, and added first tests to test implementations of configuration-based stuff (FlagUsages, specifically). Error reporter has been refactored.

test/transform/resource/before/FlagUsages.java

@@ -0,0 +1,10 @@
+//conf: lombok.Getter.flagUsage = WARNING
+//conf: lombok.experimental.flagUsage = ERROR
+public class FlagUsages {
+	@lombok.Getter String x;
+	
+	@lombok.experimental.Wither String z;
+
+	public FlagUsages(String x, String y) {
+	}
+}