*: update grpc-gateway and its import paths

Documentation/dev-guide/api_grpc_gateway.md

@@ -31,7 +31,7 @@ Generated [Swagger][swagger] API definitions can be found at [rpc.swagger.json][
 [go-client]: https://github.com/coreos/etcd/tree/master/clientv3
 [etcdctl]: https://github.com/coreos/etcd/tree/master/etcdctl
 [grpc]: http://www.grpc.io/
-[grpc-gateway]: https://github.com/gengo/grpc-gateway
+[grpc-gateway]: https://github.com/grpc-ecosystem/grpc-gateway
 [json-mapping]: https://developers.google.com/protocol-buffers/docs/proto3#json
 [swagger]: http://swagger.io/
 [swagger-doc]: apispec/swagger/rpc.swagger.json

Documentation/dev-guide/api_reference_v3.md

@@ -427,6 +427,7 @@ Empty field.
 | ----- | ----------- | ---- |
 | key | key is the first key to delete in the range. | bytes |
 | range_end | range_end is the key following the last key to delete for the range [key, range_end). If range_end is not given, the range is defined to contain only the key argument. If range_end is '\0', the range is all keys greater than or equal to the key argument. | bytes |
+| prev_kv | If prev_kv is set, etcd gets the previous key-value pairs before deleting it. The previous key-value pairs will be returned in the delte response. | bool |
 
 
 
@@ -436,6 +437,7 @@ Empty field.
 | ----- | ----------- | ---- |
 | header |  | ResponseHeader |
 | deleted | deleted is the number of keys deleted by the delete range request. | int64 |
+| prev_kvs | if prev_kv is set in the request, the previous key-value pairs will be returned. | (slice of) mvccpb.KeyValue |
 
 
 
@@ -591,6 +593,7 @@ Empty field.
 | key | key is the key, in bytes, to put into the key-value store. | bytes |
 | value | value is the value, in bytes, to associate with the key in the key-value store. | bytes |
 | lease | lease is the lease ID to associate with the key in the key-value store. A lease value of 0 indicates no lease. | int64 |
+| prev_kv | If prev_kv is set, etcd gets the previous key-value pair before changing it. The previous key-value pair will be returned in the put response. | bool |
 
 
 
@@ -599,6 +602,7 @@ Empty field.
 | Field | Description | Type |
 | ----- | ----------- | ---- |
 | header |  | ResponseHeader |
+| prev_kv | if prev_kv is set in the request, the previous key-value pair will be returned. | mvccpb.KeyValue |
 
 
 
@@ -613,6 +617,8 @@ Empty field.
 | sort_order | sort_order is the order for returned sorted results. | SortOrder |
 | sort_target | sort_target is the key-value field to use for sorting. | SortTarget |
 | serializable | serializable sets the range request to use serializable member-local reads. Range requests are linearizable by default; linearizable requests have higher latency and lower throughput than serializable requests but reflect the current consensus of the cluster. For better performance, in exchange for possible stale reads, a serializable range request is served locally without needing to reach consensus with other nodes in the cluster. | bool |
+| keys_only | keys_only when set returns only the keys and not the values. | bool |
+| count_only | count_only when set returns only the count of the keys in the range. | bool |
 
 
 
@@ -621,8 +627,9 @@ Empty field.
 | Field | Description | Type |
 | ----- | ----------- | ---- |
 | header |  | ResponseHeader |
-| kvs | kvs is the list of key-value pairs matched by the range request. | (slice of) mvccpb.KeyValue |
+| kvs | kvs is the list of key-value pairs matched by the range request. kvs is empty when count is requested. | (slice of) mvccpb.KeyValue |
 | more | more indicates if there are more keys to return in the requested range. | bool |
+| count | count is set to the number of keys within the range when requested. | int64 |
 
 
 
@@ -732,6 +739,8 @@ From google paxosdb paper: Our implementation hinges around a powerful primitive
 | range_end | range_end is the end of the range [key, range_end) to watch. If range_end is not given, only the key argument is watched. If range_end is equal to '\0', all keys greater than or equal to the key argument are watched. | bytes |
 | start_revision | start_revision is an optional revision to watch from (inclusive). No start_revision is "now". | int64 |
 | progress_notify | progress_notify is set so that the etcd server will periodically send a WatchResponse with no events to the new watcher if there are no recent events. It is useful when clients wish to recover a disconnected watcher starting from a recent known revision. The etcd server may decide how often it will send notifications based on current load. | bool |
+| filters | filter out put event. filter out delete event. filters filter the events at server side before it sends back to the watcher. | (slice of) FilterType |
+| prev_kv | If prev_kv is set, created watcher gets the previous KV before the event happens. If the previous KV is already compacted, nothing will be returned. | bool |
 
 
 
@@ -764,6 +773,7 @@ From google paxosdb paper: Our implementation hinges around a powerful primitive
 | ----- | ----------- | ---- |
 | type | type is the kind of event. If type is a PUT, it indicates new data has been stored to the key. If type is a DELETE, it indicates the key was deleted. | EventType |
 | kv | kv holds the KeyValue for the event. A PUT event contains current kv pair. A PUT event with kv.Version=1 indicates the creation of a key. A DELETE/EXPIRE event contains the deleted key with its modification revision set to the revision of deletion. | KeyValue |
+| prev_kv | prev_kv holds the key-value pair before the event happens. | KeyValue |