Start class layouts for backups and plugins API

cura/Api/Backups.py

@@ -0,0 +1,27 @@
+# Copyright (c) 2018 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+from zipfile import ZipFile
+
+from cura.Backups.BackupsManager import BackupsManager
+
+
+class Backups:
+    """
+    The backups API provides a version-proof bridge between Cura's BackupManager and plugins that hook into it.
+
+    Usage:
+        cura.Api.backups.createBackup()
+        cura.Api.backups.restoreBackup(my_zip_file, {"cura_release": "3.1"})
+    """
+
+    manager = BackupsManager()  # Re-used instance of the backups manager.
+
+    def createBackup(self) -> ("ZipFile", dict):
+        """
+        Create a new backup using the BackupsManager.
+        :return:
+        """
+        return self.manager.createBackup()
+
+    def restoreBackup(self, zip_file: "ZipFile", meta_data: dict) -> None:
+        return self.manager.restoreBackup(zip_file, meta_data)