more pruning & code refactoring (#1011)

* improve error handling to show more details

* improve the way it checks for root password

* consistant getty_override

* streamline verbose mode

* remove v4 scripts

* small tweaks

ct/create_lxc.sh

@@ -36,21 +36,14 @@ if [ -z "$VALIDTMP" ]; then
   exit 1
 fi
 
-set -o errexit
-set -o errtrace
-set -o nounset
-set -o pipefail
-shopt -s expand_aliases
-alias die='EXIT=$? LINE=$LINENO error_exit'
-trap die ERR
-
-function error_exit() {
-  trap - ERR
-  local reason="Unknown failure occurred."
-  local msg="${1:-$reason}"
-  local flag="${RD}‼ ERROR ${CL}$EXIT@$LINE"
-  echo -e "$flag $msg" 1>&2
-  exit $EXIT
+set -Eeuo pipefail
+trap 'error_handler $LINENO "$BASH_COMMAND"' ERR
+function error_handler() {
+  local exit_code="$?"
+  local line_number="$1"
+  local command="$2"
+  local error_message="${RD}[ERROR]${CL} in line ${RD}$line_number${CL}: exit code ${RD}$exit_code${CL}: while executing command ${YW}$command${CL}"
+  echo -e "\n$error_message\n"
 }
 
 function select_storage() {