fix resize bug and support custom attributes.

[icai]

resize bug:

when form field use 'col-md-x' to wrap it, resize window will have problem.

support custom attributes, for example

$(selector).tokenfield({
        autocomplete: {
            source: [
            {
                value: 'green',
                label: 'green',
                image: 'assets/images/case-1.png'
            },
            {
                value: 'red',
                label: 'red',
                image: 'assets/images/case-2.png'
            },
            {
                value: 'blue',
                label: 'blue',
                image: 'assets/images/case-3.png'
            },
            {
                value: 'kl10',
                label: 'kl10',
                image: 'assets/images/avatar-32-1.png'
            },
            {
                value: 'kw10',
                label: 'kw10',
                image: 'assets/images/avatar-32-2.png'
            },
            {
                value: 'kx10',
                label: 'kx10',
                image: 'assets/images/avatar-32-3.png'
            },{
                value: 'ww10',
                label: 'ww10',
                image: 'assets/images/avatar-34-2.png'

            },{
                value: 'pv120',
                label: 'pv120',
                image: 'assets/images/avatar-34-3.png'  
            },{
                value: 'gd123',
                label: 'gd123',
                image: 'assets/images/avatar-34.png'

            }],
            delay: 100,
            renderItem: function(ul, item){
                return $( "<li>" )
                    .append( $( "<a>" ).html( '<img src="'+ item.image +'" alt="" width="32" height="32" /> <span>' + item.label + '</span>' ) )
                    .appendTo( ul );
            }

        },
        showAutocompleteOnFocus: !0,
        delimiter: [",", " ", "-", "_"],
        template:{
            token: '<div class="token square" data-value="{{value}}"><span class="token-label"><img src="{{image}}" alt="{{label}}" width="20" height="20" /><span>{{label}}</span></span><a href="#" data-bind="close" class="close" tabindex="-1">×</a></div>'
        }
    })