java 6 support

also, to run tests you have to downgrade org.assertj:assertj-core to 1.7.0

json-path-assert/src/main/java/com/jayway/jsonassert/impl/JsonAsserterImpl.java

@@ -33,7 +33,7 @@ public class JsonAsserterImpl implements JsonAsserter {
         try {
             obj = JsonPath.<T>read(jsonObject, path);
         } catch (Exception e) {
-            throw new AssertionError(String.format("Error reading JSON path [%s]", path), e);
+            throw new AssertionError(String.format("Error reading JSON path [%s]: %s", path, e));
         }
 
         if (!matcher.matches(obj)) {

json-path/src/main/java/com/jayway/jsonpath/internal/PathRef.java

@@ -154,7 +154,7 @@ public abstract class PathRef implements Comparable<PathRef>  {
         public int compareTo(PathRef o) {
             if(o instanceof ArrayIndexPathRef){
                 ArrayIndexPathRef pf = (ArrayIndexPathRef) o;
-                return Integer.compare(pf.index, this.index);
+                return Integer.valueOf(pf.index).compareTo(this.index);
             }
             return super.compareTo(o);
         }