DS-1616 Localhost is not longer supported as a valid URL Solr

Replaced the deprecated org.apache.commons.validator.UrlValidator with the new
version from apache import org.apache.commons.validator.routines.UrlValidator
enabling local urls (localhost and internal names like mymachine, etc.)
Merge pull request #271 from abollini/DS-1616

DS-1616 Localhost is not longer supported as a valid Solr server URL