Use code-generation for CRD API and deepcopy methods (#369)

Client-go provides a https://github.com/kubernetes/code-generator package in order to provide the API to work with CRDs similar to the one available for built-in types, i.e. Pods, Statefulsets and so on.

Use this package to generate deepcopy methods (required for CRDs), instead of using an external deepcopy package; we also generate APIs used to manipulate both Postgres and OperatorConfiguration CRDs, as well as informers and listers for the Postgres CRD, instead of using generic informers and CRD REST API; by using generated code we can get rid of some custom and obscure CRD-related code and use a better API.

All generated code resides in /pkg/generated, with an exception of zz_deepcopy.go in apis/acid.zalan.do/v1

Rename postgres-operator-configuration CRD to OperatorConfiguration, since the former broke naming convention in the code-generator.

Moved Postgresql, PostgresqlList, OperatorConfiguration and OperatorConfigurationList and other types used by them into

Change the type of  the Error field in the Postgresql crd to a string, so that client-go could generate a deepcopy for it.

Use generated code to set status of CRD objects as well. Right now this is done with patch, however, Kubernetes 1.11 introduces the /status subresources, allowing us to set the status with
the special updateStatus call in the future. For now, we keep the code that is compatible with earlier versions of Kubernetes.

Rename postgresql.go to database.go and status.go to logs_and_api.go to reflect the purpose of each of those files.

Update client-go dependencies.

Minor reformatting and renaming.

glide.lock

@@ -1,8 +1,8 @@
-hash: ff2f80192f85899fb70880aabc4851672673f8ac3be257c6d9ff46ad33db94ca
-updated: 2018-08-06T15:28:34.096941+02:00
+hash: bd5394acf101795aac9da20c104a57344a6c4fd71080bf1b16845367e6360578
+updated: 2018-08-14T15:18:08.144086+02:00
 imports:
 - name: github.com/aws/aws-sdk-go
-  version: f70339bb6af843c8ab1974381b3f4fcaee2b1a41
+  version: f831d5a0822a1ad72420ab18c6269bca1ddaf490
   subpackages:
   - aws
   - aws/awserr
@@ -103,7 +103,7 @@ imports:
 - name: github.com/Sirupsen/logrus
   version: 3e01752db0189b9157070a0e1668a620f9a85da2
 - name: github.com/spf13/pflag
-  version: 9ff6c6923cfffbcd502984b8e0c80539a94968b7
+  version: 583c0c0531f06d5278b7d917446061adc344b5cd
 - name: golang.org/x/crypto
   version: c126467f60eb25f8f27e5a981f32a87e3965053f
   subpackages:
@@ -124,17 +124,10 @@ imports:
 - name: golang.org/x/text
   version: b19bf474d317b857955b12035d2c5acb57ce8b01
   subpackages:
-  - cases
-  - internal
-  - internal/tag
-  - language
-  - runes
   - secure/bidirule
-  - secure/precis
   - transform
   - unicode/bidi
   - unicode/norm
-  - width
 - name: golang.org/x/time
   version: f51c12702a4d776e4c1fa9b0fabab841babae631
   subpackages:
@@ -144,7 +137,7 @@ imports:
 - name: gopkg.in/yaml.v2
   version: 5420a8b6744d3b0345ab293f6fcba19c978f1183
 - name: k8s.io/api
-  version: 072894a440bdee3a891dea811fe42902311cd2a3
+  version: 2d6f90ab1293a1fb871cf149423ebb72aa7423aa
   subpackages:
   - admissionregistration/v1alpha1
   - admissionregistration/v1beta1
@@ -164,6 +157,7 @@ imports:
   - core/v1
   - events/v1beta1
   - extensions/v1beta1
+  - imagepolicy/v1alpha1
   - networking/v1
   - policy/v1beta1
   - rbac/v1
@@ -176,7 +170,7 @@ imports:
   - storage/v1alpha1
   - storage/v1beta1
 - name: k8s.io/apiextensions-apiserver
-  version: 06dfdaae5c2bd89e1243151ff65b9bf8ee050f28
+  version: cc9cd5d998df84cc405d398e9030d29c95acff18
   subpackages:
   - pkg/apis/apiextensions
   - pkg/apis/apiextensions/v1beta1
@@ -216,22 +210,26 @@ imports:
   - pkg/util/httpstream/spdy
   - pkg/util/intstr
   - pkg/util/json
+  - pkg/util/mergepatch
   - pkg/util/net
   - pkg/util/remotecommand
   - pkg/util/runtime
   - pkg/util/sets
+  - pkg/util/strategicpatch
   - pkg/util/validation
   - pkg/util/validation/field
   - pkg/util/wait
   - pkg/util/yaml
   - pkg/version
   - pkg/watch
+  - third_party/forked/golang/json
   - third_party/forked/golang/netutil
   - third_party/forked/golang/reflect
 - name: k8s.io/client-go
-  version: 7d04d0e2a0a1a4d4a1cd6baa432a2301492e4e65
+  version: 1f13a808da65775f22cbf47862c4e5898d8f4ca1
   subpackages:
   - discovery
+  - discovery/fake
   - kubernetes
   - kubernetes/scheme
   - kubernetes/typed/admissionregistration/v1alpha1
@@ -270,6 +268,7 @@ imports:
   - plugin/pkg/client/auth/exec
   - rest
   - rest/watch
+  - testing
   - tools/auth
   - tools/cache
   - tools/clientcmd
@@ -294,4 +293,8 @@ imports:
   version: 6702109cc68eb6fe6350b83e14407c8d7309fd1a
 - name: k8s.io/gengo
   version: 906d99f89cd644eecf75ab547b29bf9f876f0b59
+- name: k8s.io/kube-openapi
+  version: 91cfa479c814065e420cee7ed227db0f63a5854e
+  subpackages:
+  - pkg/util/proto
 testImports: []