added David as developer in Copa Server POM
Merge branch 'master' of https://github.com/UniCopa/CopaServer
added: apache derby dependency in pom
added David Knacker as Developer, added apache derby as dependency
Merge branch 'master' of https://github.com/UniCopa/CopaServer
added the init sql file to create the database
added Category,EventGroup,Event and SingleEvent Mapper xml Files
added the mybatis-config file