v7.0 (#4103)

+ DietPi-Update | Add new remote version file for updates and automatic branch migration from next version on
+ DietPi-Pre-patches | Create new pre-patches file in new separate update directory outside of DietPi core scripts directory
+ DietPi-Update | Apply automatic branch migration and new remote version + pre-patches URLs
+ DietPi-Update | Remove https://dietpi.com/ update server. Access to the GitHub repository is required anyway to download the dietpi.txt and for various software configs, when being patched or reinstalled, so it's even better to exit in the very first place instead of running into failing connections at a later stage.
+ DietPi-Update | Check desktop session via $DISPLAY variable to detect parent X session, like we do everywhere else. lxsession detects LXDE desktop sessions only.
+ DietPi-Survey_report | Add DietPi v7.0 support, matching DietPi v6.35 transition version string
+ DietPi-Update | Move APT auto-removal and systemd unit reload after incremental patches from patch file to main script, since we currently handle it as mandatory step anyway.
+ DietPi-Update | After three years, remove the DietPi pre-v6 version file. This means that these DietPi systems won't see a "new image available" message, indicating that a new image needs to be flashed, but the update check will fail instead, which practically the same can be derived from.

.meta/dietpi-survey_report

@@ -481,9 +481,16 @@
 	done
 	aSOFTWARE_NAME6_35[62]='Box86'
 	aSOFTWARE_NAME6_35[134]='Docker Compose'
-	# shellcheck disable=SC2034
 	aSOFTWARE_NAME6_35[137]='mjpg-streamer'
 
+	# v7.0 (identical to v6.35 transition version)
+	aSOFTWARE_NAME7_0=()
+	for i in "${!aSOFTWARE_NAME6_35[@]}"
+	do
+		# shellcheck disable=SC2034
+		aSOFTWARE_NAME7_0[$i]=${aSOFTWARE_NAME6_35[$i]}
+	done
+
 	Main(){
 
 		# Copy files to RAM to speed up sourcing

.update/patches

@@ -0,0 +1,7 @@
+#!/bin/bash
+{
+# DietPi-Update incremental patches to apply system and software migrations and fixes
+# Created by MichaIng / [email protected] / https://dietpi.com/
+# License: GPLv2 / https://github.com/MichaIng/DietPi#license
+exit 0
+}

.update/pre-patches

@@ -0,0 +1,7 @@
+#!/bin/bash
+{
+# DietPi-Update pre-patches that need to run before new scripts are downloaded and/or before APT upgrades
+# Created by MichaIng / [email protected] / https://dietpi.com/
+# License: GPLv2 / https://github.com/MichaIng/DietPi#license
+exit 0
+}

.update/version

@@ -0,0 +1,13 @@
+# Available DietPi version
+G_REMOTE_VERSION_CORE=7
+G_REMOTE_VERSION_SUB=0
+G_REMOTE_VERSION_RC=-1
+# Minimum DietPi version to allow update
+G_MIN_VERSION_CORE=6
+G_MIN_VERSION_SUB=-1
+# Alternative Git branch to automatically migrate to when version is too low
+G_OLD_VERSION_BRANCH='master'
+# Minimum Debian version to allow update
+G_MIN_DEBIAN=4
+# Alternative Git branch to automatically migrate to when Debian version is too low
+G_OLD_DEBIAN_BRANCH='jessie-support'