Switch to side-by-side view

--- a/third-party/rascal4ossmeter/build.properties
+++ b/third-party/rascal4ossmeter/build.properties
@@ -1,5 +1,3 @@
-source.. = src/
 output.. = bin/
 bin.includes = META-INF/,\
-               .,\
                lib/rascal.jar