Consolidate time format for API

Consolidate all the API to same time format: RFC3339, and it will be
client's responsibility to present it in more user friendly way.

Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
Upstream-commit: 9daca1222adabf3aeae97a2c4e5f4ed1bb8c15e1
Component: engine

components/engine/docs/reference/api/docker_remote_api.md

@@ -99,6 +99,8 @@ This section lists each version from latest to oldest.  Each listing includes a
 * `GET /info` Now returns `Architecture` and `OSType` fields, providing information
   about the host architecture and operating system type that the daemon runs on.
 * `GET /networks/(name)` now returns a `Name` field for each container attached to the network.
+* `GET /version` now returns the `BuildTime` field in RFC3339Nano format to make it 
+  consistent with other date/time values returned by the API.
 
 ### v1.21 API changes
 

components/engine/docs/reference/api/docker_remote_api_v1.22.md

@@ -1990,14 +1990,15 @@ Show the docker version information
     Content-Type: application/json
 
     {
-         "Version": "1.5.0",
+         "Version": "1.10.0-dev",
          "Os": "linux",
-         "KernelVersion": "3.18.5-tinycore64",
-         "GoVersion": "go1.4.1",
-         "GitCommit": "a8a31ef",
+         "KernelVersion": "3.19.0-23-generic",
+         "GoVersion": "go1.4.2",
+         "GitCommit": "e75da4b",
          "Arch": "amd64",
-         "ApiVersion": "1.20",
-         "Experimental": false
+         "ApiVersion": "1.22",
+         "BuildTime": "2015-12-01T07:09:13.444803460+00:00",
+         "Experimental": true
     }
 
 Status Codes: