fix: label displays exackly whats in item-label attribute instead of model value

[inclooder]

I couldn't make it work without those changes. I use angular 1.3.15 . Here is how i used it.

        <div     
            isteven-multi-select
            input-model="facilities"
            output-model="selectedFacilities"
            button-label="name"
            item-label="name"
            tick-property="selected"
            group-property="msGroup"
            orientation="horizontal"
            max-labels="0"
            translation="multi_select_translation"
        >