Implement version upgrade from 2.4 to 2.5

The version upgrade currently only removes the setting start_layers_at_same_position.

Contributes to issue CURA-3479.

plugins/VersionUpgrade/VersionUpgrade24to25/__init__.py

@@ -0,0 +1,44 @@
+# Copyright (c) 2017 Ultimaker B.V.
+# Cura is released under the terms of the AGPLv3 or higher.
+
+from . import VersionUpgrade24to25
+
+from UM.i18n import i18nCatalog
+catalog = i18nCatalog("cura")
+
+upgrade = VersionUpgrade24to25.VersionUpgrade24to25()
+
+def getMetaData():
+    return {
+        "plugin": {
+            "name": catalog.i18nc("@label", "Version Upgrade 2.4 to 2.5"),
+            "author": "Ultimaker",
+            "version": "1.0",
+            "description": catalog.i18nc("@info:whatsthis", "Upgrades configurations from Cura 2.4 to Cura 2.5."),
+            "api": 3
+        },
+        "version_upgrade": {
+            # From              To                 Upgrade function
+            ("preferences", 4): ("preferences", 5, upgrade.upgradePreferences),
+            ("quality", 2):     ("quality", 3,     upgrade.upgradeInstanceContainer),
+            ("variant", 2):     ("variant", 3,     upgrade.upgradeInstanceContainer), #We can re-use upgradeContainerStack since there is nothing specific to quality, variant or user profiles being changed.
+            ("user", 2):        ("user", 3,        upgrade.upgradeInstanceContainer)
+        },
+        "sources": {
+            "quality": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"./quality"}
+            },
+            "preferences": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"."}
+            },
+            "user": {
+                "get_version": upgrade.getCfgVersion,
+                "location": {"./user"}
+            }
+        }
+    }
+
+def register(app):
+    return { "version_upgrade": upgrade }