Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

application/constants/constants.go

@@ -0,0 +1,34 @@
+package constants
+
+// These values will be injected at build time, DO NOT EDIT.
+
+// BackendVersion 当前后端版本号
+var BackendVersion = "4.0.0-alpha.1"
+
+// IsPro 是否为Pro版本
+var IsPro = "false"
+
+var IsProBool = IsPro == "true"
+
+// LastCommit 最后commit id
+var LastCommit = "000000"
+
+const (
+	APIPrefix      = "/api/v4"
+	APIPrefixSlave = "/api/v4/slave"
+	CrHeaderPrefix = "X-Cr-"
+)
+
+const CloudreveScheme = "cloudreve"
+
+type (
+	FileSystemType string
+)
+
+const (
+	FileSystemMy           = FileSystemType("my")
+	FileSystemShare        = FileSystemType("share")
+	FileSystemTrash        = FileSystemType("trash")
+	FileSystemSharedWithMe = FileSystemType("shared_with_me")
+	FileSystemUnknown      = FileSystemType("unknown")
+)