update ignore file

Author: Andreas Dann

.gitignore

@@ -194,4 +194,7 @@ buildNumber.properties
 
 ### allow the ecj and jdt core jar ###
 !src/test/resources/ecj-3.15.1.jar
-!src/test/resources/org.eclipse.jdt.core-3.15.0.jar
+!src/test/resources/org.eclipse.jdt.core-3.15.0.jar
+/sootdiff.iml
+**/sootOutput
+.idea