FIX: todo_completion problem with Bash 3.1

Regexp matching changed from 3.1 to 3.2. Make it work for Bash 3.1 by using an intermediate variable, as in 394c4c748a.
Cp. http://tech.groups.yahoo.com/group/todotxt/message/4211

todo.sh

@@ -1105,7 +1105,7 @@ case $action in
     TOTAL=$( sed -n '$ =' "$TODO_FILE" )
     PADDING=${#TOTAL}
 
-    post_filter_command="${post_filter_command:-}${post_filter_command:+ | }awk -v TOTAL=$TOTAL -v PADDING=$PADDING '{ \$1 = sprintf(\"%\" PADDING \"d\", (\$1 > TOTAL ? 0 : \$1)); print }' "
+    post_filter_command="awk -v TOTAL=$TOTAL -v PADDING=$PADDING '{ \$1 = sprintf(\"%\" PADDING \"d\", (\$1 > TOTAL ? 0 : \$1)); print }' "
     cat "$TODO_FILE" "$DONE_FILE" | TODOTXT_VERBOSE=0 _format '' "$PADDING" "$@"
 
     if [ $TODOTXT_VERBOSE -gt 0 ]; then
@@ -1149,7 +1149,7 @@ case $action in
     shift ## was "listpri", new $1 is priority to list or first TERM
 
     pri=$(printf "%s\n" "$1" | tr 'a-z' 'A-Z' | grep -e '^[A-Z]$' -e '^[A-Z]-[A-Z]$') && shift || pri="A-Z"
-    post_filter_command="${post_filter_command:-}${post_filter_command:+ | }grep '^ *[0-9]\+ ([${pri}]) '"
+    post_filter_command="grep '^ *[0-9]\+ ([${pri}]) '"
     _list "$TODO_FILE" "$@"
     ;;
 

todo_completion

@@ -14,14 +14,15 @@ _todo()
         rm depri dp do help list ls listaddons listall lsa listcon  \
         lsc listfile lf listpri lsp listproj lsprj move \
         mv prepend prep pri p replace report shorthelp"
+    local -r MOVE_COMMAND_PATTERN='^(move|mv)$'
 
     local _todo_sh=${_todo_sh:-todo.sh}
     local completions
     if [ $COMP_CWORD -eq 1 ]; then
         completions="$COMMANDS $(eval TODOTXT_VERBOSE=0 $_todo_sh command listaddons) $OPTS"
     elif [[ $COMP_CWORD -gt 2 && ( \
-        "${COMP_WORDS[COMP_CWORD-2]}" =~ ^(move|mv)$ || \
-        "${COMP_WORDS[COMP_CWORD-3]}" =~ ^(move|mv)$ ) ]]; then
+        "${COMP_WORDS[COMP_CWORD-2]}" =~ $MOVE_COMMAND_PATTERN || \
+        "${COMP_WORDS[COMP_CWORD-3]}" =~ $MOVE_COMMAND_PATTERN ) ]]; then
         # "move ITEM# DEST [SRC]" has file arguments on positions 2 and 3.
         completions=$(eval TODOTXT_VERBOSE=0 $_todo_sh command listfile)
     else