Make auto-update git aware (#133)

* Make auto-update git aware
Fixes #106

* Some slight tweaking and bug-fixing

global.sh

@@ -24,22 +24,30 @@ parse_yaml() {
 
 # automatic update function
 gitupdate() {
-git remote add upstream https://github.com/jailmanager/jailman.git > /dev/null 2>&1
+if [ "$(git config --get remote.origin.url)" = "https://github.com/Ornias1993/jailman" ]
+then
+	echo "The repository has been moved, please reinstall using the new repository: jailmanager/jailman"
+	exit 1
+fi
+if [ "$1" = "" ] || [ "$1" = "HEAD" ];
+then
+	echo "Detatched or invalid GIT HEAD detected, please reinstall"
+else
 	echo "checking for updates using Branch: $1"
-git fetch upstream > /dev/null 2>&1
+	git fetch > /dev/null 2>&1
 	git update-index -q --refresh > /dev/null 2>&1
 	CHANGED=$(git diff --name-only "$1")
 	if [ -n "$CHANGED" ];
 	then
 		echo "script requires update"
 		git reset --hard > /dev/null 2>&1
-    git checkout "${1}" > /dev/null 2>&1
 		git pull > /dev/null 2>&1
 		echo "script updated, please restart the script manually"
 		exit 1
 	else
 		echo "script up-to-date"
 	fi
+fi
 }
 
 jailcreate() {

jailman.sh

@@ -20,8 +20,7 @@ if ! [ "$(id -u)" = 0 ]; then
 fi
 
 # Auto Update
-BRANCH="upstream/minor-dev"
-gitupdate "${BRANCH}"
+gitupdate $(git for-each-ref --format='%(upstream:short)' "$(git symbolic-ref -q HEAD)") || exit 1
 
 # If no option is given, point to the help menu
 if [ $# -eq 0 ]