Performance improvement of token cleanup:

an alternative token cleanup mechanism designed to maintain a very compact memory footprint while performing cleanup in consecutive runs of the cleanup thread. This serves to address OutOfMemoryException issues of the original token cleanup mechanism when process is under load. Also, added cleanup of the authentication_holder table.

Conflicts:
	openid-connect-common/src/main/java/org/mitre/oauth2/model/AuthenticationHolderEntity.java
	openid-connect-common/src/main/java/org/mitre/oauth2/repository/AuthenticationHolderRepository.java
	openid-connect-server/src/main/java/org/mitre/oauth2/repository/impl/JpaAuthenticationHolderRepository.java
	openid-connect-server/src/main/java/org/mitre/oauth2/service/impl/DefaultOAuth2ProviderTokenService.java
fixed bad JPQL in auth holder cleanup class

Conflicts:
	openid-connect-common/src/main/java/org/mitre/oauth2/model/AuthenticationHolderEntity.java
simple cache for stats
updated stats service to have a resettable cache triggered by other service events

Conflicts:
	openid-connect-server/src/main/java/org/mitre/oauth2/service/impl/DefaultOAuth2ClientDetailsEntityService.java
	openid-connect-server/src/main/java/org/mitre/oauth2/web/OAuthConfirmationController.java
	openid-connect-server/src/main/java/org/mitre/openid/connect/service/impl/DefaultApprovedSiteService.java
stats on home page are now loaded in the background (makes main site load much faster)
fixed stats pluralization flub
happy new year, 1.0! (finally)

Signed-off-by: Justin Richer <jricher@mit.edu>