Remove dependency of reflection for TestNG

[krmahadevan]

The PaxExam listener makes use of reflection to disable configuration methods.

This is NOT needed because the TestNG API has Provided setters via which these can be set.

The reason why this change is required is because TestNG in its upcoming version is going to be Changing the data type of these two attributes viz “m_beforeTestMethods” and “m_afterTestMethods”