Update readme for v12

[#78056840]
Set -e in start scripts
Remove mysql.server, write state file only after successful startup

Also bump the mariadb_ctrl
[#78600746]
Used shared helpers with cf-riak-cs-release
Bump src/cf-mysql-broker

Bump cloudfoundry/cf-mysql-broker:
  David Sabeti and Raina Masand:
     Add new db migration to fix null db_names ( Travis Success: https://travis-ci.org/cloudfoundry/cf-mysql-broker/builds/35591886 )
Bump broker to include security issue

[#78744830]
Bump submodule to include poll database before running upgrade script

[#78655542]
Merge tag 'v14'

Conflicts:
	test/acceptance-tests/vendor/src/github.com/onsi/ginkgo/LICENSE
	test/acceptance-tests/vendor/src/github.com/onsi/ginkgo/MIT.LICENSE
	test/acceptance-tests/vendor/src/github.com/onsi/gomega/LICENSE
	test/acceptance-tests/vendor/src/github.com/onsi/gomega/MIT.LICENSE
	test/acceptance-tests/vendor/src/github.com/onsi/gomega/matchers/support/goraph/MIT.LICENSE
moving known issues to wiki
Merge commit '688f043'