[MRM-494] leaving repository ID blank on the add repository page goes to the edit page where ID cannot be edited Overhauled repository admin actions to be more consistent with best practices. Split into seperate actions. Added -validation.xml files. Added unit tests.
maven/archiva/trunk/archiva-web/archiva-webapp/src/main/java/org/apache/maven/archiva/web/action/admin/repositories/AbstractConfigureRepositoryAction.java
maven/archiva/trunk/archiva-web/archiva-webapp/src/main/resources/org/apache/maven/archiva/web/action/admin/repositories/