Add initial support for a virtual attribute subsystem, and implement a few ...

neil_a_wilson

03.52.2007 e1ea3e0d8999105f144d2be98e0286928b8319ed

opends/src/server/org/opends/server/api/VirtualAttribute.java does not exist in tree 0bd13e1062da005f69ec8a15a1b21f61b992e75f