ILSelectField and multiple: true

> Dear Nicolas,
>
> ILSelectField>>#fieldContents can only add elements but never remove
> them. This means that unselecting an item on configuration is not
> possible at all. I am using the below patch.
>
>
> diff --git a/More/Formula/ILSelectField.st b/More/Formula/
> ILSelectField.st
> index e5e7b1e..2afa002 100644
> --- a/More/Formula/ILSelectField.st
> +++ b/More/Formula/ILSelectField.st
> @@ -60,14 +60,17 @@ ILOptionField subclass: ILSelectField [
>
>      fieldContents [
>         <category: 'building'>
> -       ^[:e |
> +       ^[:e | | val |
>             e select build: [:select |
> +               val := self value.
>                 self isMultiple ifTrue: [
> +                   self value: OrderedCollection new.
>                     select beMultiple].
> +
>                 self options do: [:each |
>                     select option
>                         selected: (self isMultiple
> -                           ifTrue: [self value includes: each]
> +                           ifTrue: [val includes: each]
>                             ifFalse: [self value = each]);
>                         text: (self optionLabelBlock value: each);
>                         action: [self isMultiple
>