Feature request: exposed flattenJSON method

[jtrumbull]

@djhvscf: I forked this repository and was going to create some PRs. Didn't want to get to far if this is something that you are working on -or did't want in the extension.

BootstrapTable.prototype.flattenJSON = function(data) {
    if (Object.prototype.toString.call(data) === "[object Object]") {
        return sd.flat(data);
    }
    return sd.flatHelper(data);
};

$.fn.bootstrapTable.methods.push('flattenJSON');

Usage:

// On Array
$('#table').bootstrapTable('flattenJSON', [
    {...},
    {...},
    {...}
]);

// or Object
$('#table').bootstrapTable('flattenJSON', {...});