Updating POM

Use correct location of maven xsd
Update to mybatis parent 22-SNAPSHOT
Update to mybatis 3.2.8
Update hsqldb to 2.3.2
Removed exclusions on log4j.  Those were left over from prior version
where log4j defined dependencies incorrectly.  It is no longer an issue.
ignore velocity.log
Switch tabs to spaces
Added missing serialization version uid
Removed unused import
Add type to iterator