SONAR-5007 - added createdAt and updatedAt fields for ActiveRuleDto

Conflicts:
	sonar-server/src/test/java/org/sonar/server/qualityprofile/RuleActivatorMediumTest.java
SONAR-5007 - Reverted final modifier for base method because of legacy @Mock
SONAR-5007 - Ignore test for SONAR-5183
fix quality flaw (possible NPE)
fix quality flaw (possible NPE)