I suggest another change... this will insert a "clear" button next to the search term.. most people will find it normal to have that. Plus is it inconvenient having to "backspace" to clear a search term.

=================================================================

        // Search input
        if ( o.searchable ) {
                that.input = that.wrapper.querySelector(".dataTable-input");
                if ( that.input ) {
                        util.on(that.input, 'keyup', function(e) {
                                that.search(this.value);
                        });

             // new button
            /////////////////////////////////////////////////
            that.clearform = that.wrapper.querySelector(".dataTable-clear");
                if ( that.clearform ) {
                                util.on(that.clearform, 'click', function(e) {
                                                that.input.value='';
                                                this.value='';
                                                that.search(this.value);
                                });


                }


                }

        }

=================================================================

        // Searchable
        if (o.searchable) {
                var sNull = '';

                // Changed the next line
                ///////////////////////////////////////////////////////////////
               var form = "<div class='dataTable-search'><input class='dataTable-input' placeholder='"+o.labels.placeholder+"' type='text'><button class='dataTable-input dataTable-clear'>Clear</button></div>";

                // Search input placement
                template = template.replace("{search}", form);
        } else {
                template = template.replace("{search}", "");