Issue #3 Remove user agent from RequestCounts
- Data Definition rename 'userReleasedForAddressAndAgentAt' by
'userReleasedForAddressAndCookieAt'
		replace column 'agent' by 'cookieToken' varchar 40
		long enough to hold bin2hex($this->secureRandom->nextBytes(20));
//CsrfProvider uses SHA1 , is 20 bytes
- RequestCountsRepository replaced agent by cookieToken
	::isUserReleasedForAgentFrom renamed to ::isUserReleasedByCookieFrom
	::getIdWhereDateAndUsernameAndIpAddressAndAgent renamed to
::getIdWhereDateAndUsernameAndIpAddressAndCookie 
	::qbWhereDateAndUsernameAndIpAddressAndAgent renamed to
qbWhereDateAndUsernameAndIpAddressAndCookie
	::findByDateAndUsernameAndIpAddressAndAgent removed
- TresholdsGovernor now uses UsernameBlockedForCookieException
	>>isUserReleasedOnAgent renamed to >>isUserReleasedByCookie, default
false
	>>failureCountForUserOnAgent renamed to >>failureCountForUserByCookie
	>>allowReleasedUserOnAgentFor renamed to >>allowReleasedUserByCookieFor
	>>distinctiveAgentMinLength removed
	::isAgentDistinctive removed
	::releaseUserNameForIpAddressAndUserAgent renamed to ::
	column 'userReleasedForAddressAndAgentAt' replaced by
'userReleasedForAddressAndCookieAt'
	call to :getIdWhereDateAndUsernameAndIpAddressAndAgent replaced by
::getIdWhereDateAndUsernameAndIpAddressAndCookie 
	>>isUserReleasedOnAddress default false
	::initFor no longer derives isUserReleasedByCookie if not
allowReleasedUserByCookieFor
		no longer derives isUserReleasedOnAddress if not
allowReleasedUserOnAddressFor
- UsernameBlockedForAgentException renamed to
UsernameBlockedForCookieException
- UsernamePasswordFormAuthenticationGuard::attemptAuthentication 
	no longer passes user agent, passes empty string because setting and
getting cookies not yet implemented
- Configuration::getConfigTreeBuilder removed
allowReleasedUserOnAgentFor, distinctiveAgentMinLength
- TresholdsGovernorTest removed distinctiveAgentMinLength setting
	replaced renameed TresholdsGovernor properties and the renamed
Exception
	::testCheckAuthenticationWithUserReleasedOnIpAddressAndAgent renamed to
::testCheckAuthenticationWithUserReleasedOnIpAddressAndCookie
	::testCheckAuthenticationWithUserReleasedOnIpAddressAndCookie removed
section for  $this->governer->distinctiveAgentMinLength = 7;
	::testBlockingDurations because no check for cookieToken min length now
expecting:
		failureCountForUserName = 6 ; 5 seconds less then 10 days: 2
		failureCountForUserByCookie = 2 ;  5 seconds less then 10 days: 1
	::testReleaseDurations because no check for cookieToken min length now
expecting:
		failureCountForUserByCookie = 2
- doc/Installation.md removed allowReleasedUserOnAgentFor and
distinctiveAgentMinLength
- doc/Counting and deciding.md adapted to the release by user agent
being replaced by release by cookie token and not being used
- Readme.md changed requirement with respect to doctrine, 
	removed release note  with respect to unit tests not running from the
command line