Added the MDMP classifier along with unit tests

The actual classifier: Minimum Distance Rule using Moore-Penrose
Inverse (MDMP) classifier from Srivastava and Kubokawa (2007)
Added the MDMEB classifier along with unit tests

The actual classifier: Minimum Distance Rule using Modified Empirical
Bayes (MDMEB) classifier from Srivastava and Kubokawa (2007)
Added more detailed contexts to unit tests
Forgot to add Rd file for MDMEB classifier