Merge branch 'master' into improve-tolerations-doc

.gitignore

README.md

docs/administrator.md

docs/diagrams/Makefile

docs/diagrams/logo.png

docs/diagrams/operator.png

docs/diagrams/operator.tex

docs/diagrams/pod.png

docs/diagrams/pod.tex

docs/gsoc-2019/ideas.md

docs/index.md

docs/reference/cluster_manifest.md

docs/reference/operator_parameters.md

manifests/postgresql-operator-default-configuration.yaml

pkg/apis/acid.zalan.do/v1/operator_configuration_type.go

pkg/cluster/cluster.go

pkg/cluster/k8sres.go

pkg/cluster/pod.go

pkg/cluster/util.go

pkg/controller/operator_config.go