Merge pull request #278 from ericbn/master

Using StringBuilder to concatenate strings in javalite-common and correction in XmlEntities convertion from int to char
fixed after a pull request merge
Updated .gitignore and activejdbc/pom.xml
Using StringBuilder, updated Model.ToJson() and Model.toXml() to be symmetric
Reviewed Collections.list()
Added new join methods to Util
Pending: documentation