Allow commandLine interface to share configuration file with application...

.... Removes need to duplicate properties in a specific file for Liquibase.

When using the commandline interface its quite likely that you have the configuration of the application at hand. But that can not be used at the moment, as parsing of the properties file fails on any unknown parameter. 
So at present you'd need to specify the database connection parameters in two files, one for liquibase and one for the application, which makes configuration management a little more difficult than necessary.

Allowing non-strict parsing is one way to solve this (using a liquibase. prefix would be another, but thats more intrusive).