Issue 81: Allow using encrypted password in the dbdeploy maven plugin

Issue 81: Allow using encrypted password in the dbdeploy maven plugin pom configuration. Excepts encryptionKey as a VM argument such as -DencryptionKey=mysecretkey and the password in the pom.xml is enclosed within ENC() such as ENC(G7+yPDK2Ci8fpu9OV67ZNw==).