TT#37257 Change default debug output style to be more informative

The new output will will provide details about the executed line in code:

> root@spce:~# bash -x /usr/sbin/ngcp-status
> + export 'PS4=+\t (${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): } '
> + PS4='+\t (${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): } '
> +10:43:04 (/usr/sbin/ngcp-status:7): main():  set -e
> +10:43:04 (/usr/sbin/ngcp-status:8): main():  set -u
> +10:43:04 (/usr/sbin/ngcp-status:10): main():  export LC_ALL=C.UTF-8
> +10:43:04 (/usr/sbin/ngcp-status:10): main():  LC_ALL=C.UTF-8
> +10:43:04 (/usr/sbin/ngcp-status:13): main():  '[' -r /etc/debian_version ']'
> ...

Change-Id: I9aeb903703844a8ba0c43832cf1eec897520cc40

templates/scripts/includes/deployment.sh

@@ -232,14 +232,14 @@ die() {
 enable_trace() {
   if "${DEBUG_MODE}" ; then
     set -x
-    PS4='+\t '
+    export PS4='+\t (${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): } '
   fi
 }
 
 disable_trace() {
   if "${DEBUG_MODE}" ; then
     set +x
-    PS4=''
+    export PS4=''
   fi
 }