RUBY-1024 fixed and simplified WebFrontend/QueueTime metric recording

Conflicts:
	lib/new_relic/agent/instrumentation/controller_instrumentation.rb
	test/multiverse/suites/sinatra/sinatra_test.rb
	test/new_relic/agent/agent_test_controller_test.rb
	test/new_relic/agent/instrumentation/controller_instrumentation_test.rb
RUBY-1024 make sure not to define the queue time constants more than once
RUBY-1024 make sure not to define the queue time constants more than once
RUBY-1024 changelog and version for 3.5.7 beta

Conflicts:
	CHANGELOG