added test cases from A3 and modified test.py

Test.py

...3/a3/J1_5_AmbiguousName_DefaultPackageNotVisible/Bar.java

.../a3/J1_5_AmbiguousName_DefaultPackageNotVisible/Main.java

...J1_5_AmbiguousName_DefaultPackageNotVisible/Main/Bar.java

.../J1_5_AmbiguousName_DefaultPackageNotVisible/foo/Bar.java

Tests/A3/a3/J1_5_AmbiguousName_FieldVsType.java

Tests/A3/a3/J1_5_AmbiguousName_FieldVsType_Initializer.java

Tests/A3/a3/J1_5_AmbiguousName_LocalVsField.java

Tests/A3/a3/J1_5_AmbiguousName_LocalVsField_SameLine.java

Tests/A3/a3/J1_5_AmbiguousName_LocalVsType.java

Tests/A3/a3/J1_5_ForwardReference_ArrayLength.java

Tests/A3/a3/J1_5_ForwardReference_EqualInfix.java

...3/a3/J1_5_ForwardReference_ExplicitThis_InAssignment.java

Tests/A3/a3/J1_5_ForwardReference_SameLine.java

Tests/A3/a3/J1_6_Assignable_Object_ObjectArray.java

Tests/A3/a3/J1_6_AssignmentInArrayLength.java

Tests/A3/a3/J1_6_AssignmentInNotArrayLength.java

Tests/A3/a3/J1_6_ProtectedAccess_ImplicitSuper/A.java

Tests/A3/a3/J1_6_ProtectedAccess_ImplicitSuper/B.java

Tests/A3/a3/J1_6_ProtectedAccess_ImplicitSuper/C.java