changed to group participant. let's see if it is ok.
unused imports.
Merge branch 'master' of https://github.com/xaloon/sports-component

Conflicts:
	sports-persistence/src/main/java/org/xaloon/sports/persistence/dao/GroupDao.java
	sports-persistence/src/main/java/org/xaloon/sports/persistence/query/GroupQuery.java
	sports-persistence/src/main/java/org/xaloon/sports/persistence/query/impl/GroupQueryImpl.java
	sports-persistence/src/main/java/org/xaloon/sports/persistence/query/impl/TeamQueryImpl.java
	sports-persistence/src/test/java/org/xaloon/sports/persistence/query/impl/CustomQueryImplTest.java