Issue #2 Implemented the MD5 hash algorithm check

<a href="https://commons.apache.org/proper/commons-codec/apidocs/org/apache/commons/codec/digest/Md5Crypt.html">Md5Crypt</a> is based on the same algorithm by Poul Henning-Kemp as the code at ftp://ftp.arlut.utexas.edu/pub/java_hashes/MD5Crypt.java . Since the project already imports Commons-Codec I thought it would be helpful if we used it here instead.