Fix OPENDJ-508 - Searches that rely on searchable virtual attribute may be slow. For those searchable virtual attributes that can be faster than indexing (like when always matching a single entry), we process them before indexes. For the others, we fall back to them when indexes are not enough. Changes include a little bit of tidy up of comments and IDE warnings.

Minor cleanup of some virtual attribute providers: * avoid unnecessary allocation of hashsets * stop PWP VA from logging errors when it encounters LDAP PTA policies (log verbose trace instead).

Final refactoring work for OPENDJ-262: Implement pass through authentication (PTA) Introduce AuthenticationPolicyState abstract class for managing bind context. This interface will allow PTA implementations to persist state to the user's entry as needed (e.g. cached passwords).

Initial checkpoint of work for OPENDJ-262: Implement pass through authentication (PTA) Refactor PasswordPolicy implementation so that we now have a common parent type, "AuthenticatioPolicy", which will act as a common entry point for all authentication policies. In particular, password policies can be thought of as a specific type of authentication policy: one where authentication and the user's credentials are managed locally. PTA can be thought of as a non-local authentication policy: the password is managed by a third party. With this change we still only have one type of authentication policy and no attempt has been made to refactor code which uses it. More specifically, code such as the local backend WFE just type-casts the authentication policy to a password policy. Another implication of this change is that sub-entry based password policies now automatically inherit run-time changes made to the default password policy, whereas before a server restart was required.

Last batch of changes for this week. This adds support for the IETF based Password Policy for LDAP as SubEntry. Also resolves the following issues : - 4544 : initializeBackend() should not set JE env config params directly. - 4478 : ECL in draft compat mode / search lastchangenumber can be very long - 4538 : Virtual attributes not retrieved when entry cache configured - 4547 : Search Filter Matching differ for cn=Directory Manager and plain user. - 4514 : Logs shows unexpected message with replication monitoring data missing (Partial fix) - 4534 : Replication using security does not work after server restart - 4516 : SEVERE_ERROR: servers (...) have the same ServerId In addition, they also improve reliability and performance in various areas including CollectiveAttributes, Virtual Attributes and Subentries management, Schema loading, Replication...