To achieve this, we have to make sure that the following is not set:
* `zstyle ':completion:*:default' list-prompt '...'`
otherwise long completion lists will be paginated (without prompting).
The list is considered too long when it's greater than `${LISTMAX}`,
which has a value of 100 by default.
Also remove options being set (or unset) that are already the default,
namely:
* `AUTO_MENU <D>`
* `AUTO_LIST (-9) <D>`
* `MENU_COMPLETE (-Y)`
And remove the space character from the beginning of the messages.
Fixes#136. Closes#248