Minor code changes

A couple minor attempts at improvement.  Please excuse the "strip trailing whitespace" editor setting.

I removed the exception handling from the updated log level setting as it does not appear that the new API could possibly throw an IllegalArgumentException.

The motivation for the .gitignore patterns came from when I tried to build an internal version of Liquibase using `mvn versions:set`.  They're a straight copy from https://github.com/github/gitignore/blob/master/Maven.gitignore.