PLT-2241 Refactored statuses into a more real-time system (#3573)

* Refactored statuses into a more real-time system

* Updated package.json with correct commit and fixed minor bug

* Minor updates to statuses based on feedback

* When setting status online, update only LastActivityAt if status already exists

model/status.go

@@ -0,0 +1,42 @@
+// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package model
+
+import (
+	"encoding/json"
+	"io"
+)
+
+const (
+	STATUS_OFFLINE    = "offline"
+	STATUS_AWAY       = "away"
+	STATUS_ONLINE     = "online"
+	STATUS_CACHE_SIZE = 10000
+)
+
+type Status struct {
+	UserId         string `json:"user_id"`
+	Status         string `json:"status"`
+	LastActivityAt int64  `json:"last_activity_at"`
+}
+
+func (o *Status) ToJson() string {
+	b, err := json.Marshal(o)
+	if err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}
+
+func StatusFromJson(data io.Reader) *Status {
+	decoder := json.NewDecoder(data)
+	var o Status
+	err := decoder.Decode(&o)
+	if err == nil {
+		return &o
+	} else {
+		return nil
+	}
+}