Checkpoint commit for OPENDJ-1536: Rename ErrorResultException to LdapException and remove ErrorResultIOException

Simplify config framework exception hierarchy by removing and pulling up the following exceptions: * DefaultBehaviorException * IllegalPropertyValueException * IllegalPropertyValueStringException * PropertyIsMandatoryException * PropertyIsReadOnlyException * PropertyIsSingleValuedException * UnknownPropertyDefinitionException

Minor changes: * rename remaining "admin" to "config" * move all config related files under "config" source and output folders * use META-INF/services for config manifest file allowing us to use ServiceLoader in future * fixed redundant imports from earlier commit.

Reorganize opendj-config packaging, removing all references to opends and renaming admin to config