Columns to be searched configured by data-attribute of search input 

Previously, it seems, only all columns could be searched, even if there were preparations made to specify certain columns to be searched (and exclude the others). With these changes, a data-searchColumn attribute can be defined on every search input. In this data-attribute a json-object specifies the columns to be searched, like this:<code>&lt;input type='text' class='search' data-searchColumn='{'name':true}' /&gt;</code>