CLOUDSTACK-5923: CS doesn't do master switch for XS any more, CS will depend on XS HA to do master switch, XS HA needs to be enabled.
Changed "authenticate" method to return both - result of authentication, and action to perform when authentication failed - to the accountManagerImpl. Only if authenicators request INCREMENT_INCORRECT_LOGIN_ATTEMPT_COUNT, the incorrect_login_attempts parameter will be increased

Signed-off-by: Alena Prokharchyk <alena.prokharchyk@citrix.com>

Conflicts:
	plugins/user-authenticators/ldap/src/org/apache/cloudstack/ldap/LdapAuthenticator.java
	plugins/user-authenticators/md5/src/com/cloud/server/auth/MD5UserAuthenticator.java
	plugins/user-authenticators/plain-text/src/com/cloud/server/auth/PlainTextUserAuthenticator.java
	plugins/user-authenticators/sha256salted/src/com/cloud/server/auth/SHA256SaltedUserAuthenticator.java
	server/src/com/cloud/server/auth/UserAuthenticator.java
	server/src/com/cloud/user/AccountManagerImpl.java