ENH: Better completion for custom add-ons via new listaddons command.

The todo_completion had the problem that it didn't consider the todo.cfg itself for the location of TODO_ACTIONS_DIR, it just tried the default location or a globally exported config value. With the injection of custom configuration now in place, we can actually delegate the listing to todo.sh itself.
The added built-in "listaddons" command is used for that; it may also be helpful for troubleshooting or to find out about available add-ons. (But the help / shorthelp commands offer more information.)

Additionally, completion is now more precise; only executable actions and no subdirs are listed now; this is also covered by the enhanced test.

The last bonus: The custom add-on actions are now only determined when there's actually completion of commands.

.gitignore

@@ -1,6 +1,3 @@
 VERSION-FILE
 tests/test-results
 tests/trash\ directory.*
-done.txt
-report.txt
-todo.txt

tests/t6030-completion-tasks.sh

@@ -14,7 +14,6 @@ notice the sunflowers +sunflowers @outside @garden +shared +landscape
 (C) 2012-02-28 @outside mow the lawn
 x 2012-02-21 +herbs @oriental buy spices
 x 2012-02-28 2012-02-21 +slack @home watch tv
-2012-02-28 +herbs buy cinnamon @grocer
 EOF
 test_todo_completion 'simple task' 'todo.sh list 1' '"1 # simple task"'
 test_todo_completion 'remove projects and contents from task' 'todo.sh list 2' '"2 # notice the sunflowers"'
@@ -22,6 +21,5 @@ test_todo_completion 'keep priority' 'todo.sh list 3' '"3 # (B) smell the flower
 test_todo_completion 'keep priority and remove timestamp' 'todo.sh list 4' '"4 # (C) mow the lawn"'
 test_todo_completion 'keep done marker and remove done date' 'todo.sh list 5' '"5 # x buy spices"'
 test_todo_completion 'keep done marker and remove timestamp and done date' 'todo.sh list 6' '"6 # x watch tv"'
-test_todo_completion 'remove add date' 'todo.sh list 7' '"7 # buy cinnamon"'
 
 test_done

todo_completion

@@ -58,8 +58,8 @@ _todo()
                             # a safety check of the ls action output.
                             local todo=$( \
                                 eval TODOTXT_VERBOSE=0 $_todo_sh '-@ -+ -p -x command ls "^ *${cur} "' | \
-                                sed -e 's/^ *[0-9]\{1,\} //' -e 's/^\((.) \)\{0,1\}[0-9]\{2,4\}-[0-9]\{2\}-[0-9]\{2\} /\1/' \
+                                sed -e 's/^ *[0-9]\+ //' -e 's/\((.) \)[0-9]\{2,4\}-[0-9]\{2\}-[0-9]\{2\} /\1/' \
-                                    -e 's/^\([xX] \)\([0-9]\{2,4\}-[0-9]\{2\}-[0-9]\{2\} \)\{1,2\}/\1/' \
+                                    -e 's/\([xX] \)\([0-9]\{2,4\}-[0-9]\{2\}-[0-9]\{2\} \)\{1,2\}/\1/' \
                                     -e 's/[[:space:]]*$//' \
                                     -e '1q' \
                             )
@@ -85,9 +85,6 @@ complete -F _todo todo.sh
 # If you define an alias (e.g. "t") to todo.sh, you need to explicitly enable
 # completion for it, too:
 #complete -F _todo t
-# It is recommended to put this line next to your alias definition in your
-# ~/.bashrc (or wherever else you're defining your alias). If you simply
-# uncomment it here, you will need to redo this on every todo.txt update!
 
 # If you have renamed the todo.sh executable, or if it is not accessible through
 # PATH, you need to add and use a wrapper completion function, like this: