OPENDJ-879 (CR-1600) Add HTTP access log


Consolidated common code for the *LogPublisher classes prior to implementing the HTTP access log.


LogPublisher.java: ADDED
Unify all the *LogPublisher classes.
Implements Closeable.

AccessLogPublisher.java, DebugLogPublisher.java, ErrorLogPublisher.java:
Now implementing LogPublisher.
Pulled up isConfigurationAcceptable(), initialize*LogPublisher() renamed to initializeLogPublisher(), close(), getDN().
Removed syntactic/spaces differences between all these classes to better expose their commonalities.
Used Set and MAp interfaces rather than comcrete classes.

AccessLogger.java, ErrorLogger.java, DebugLogger.java:
In isJavaClassAcceptable() and getAccessPublisher(), replaced method invocations via reflection by direct method calls.

TextAccessLogPublisher.java, TextAuditLogPublisher.java, TextErrorLogPublisher.java, ThreadFilterTextErrorLogPublisher.java, TextDebugLogPublisher.java, ConsoleDebugLogPublisher.java:
Consequence of renaming the initialize*LogPublisher() methods, or generecizing the isConfigurationAcceptable() methods in their parent classes.