Issue #6 Add a function for clean-up of the RequestCounts 
- TresholdsGovernor::packData added
	::releaseUserNameForIpAddressAndCookie now only adds Releases if
allowReleasedUserByCookieFor or allowReleasedUserOnAddressFor
- TresholdsGovernorTest::testPackData added
- Tests\Mock\MockGateway added
- doc/Installation.md added index releasedAt to secu_releases table
definition
	added index byUsernameAndCookie to secu_requestcounts table definition