Finds if the index is inside one of the items
Items should be in the same format as returned from util.findPositions

@param {Number} index The index to check
@param {Array<{start: Number, end: Number}>} items The items to search
@returns {*} The start/end position if index is inside an item, else false
function inPosition(index, items) {
    for (var i = 0; i < items.length; i++) {
        var item = items[i];
        if (index >= item.start && index <= item.end) return item;
    }
    return false;
}