Update Grocery_CRUD.php

adding functions to customize form add and edit
function class_add_field 
function attribut_add_field
function class_edit_field 

How to use:
$fieldForm=array('Title','Super_categorie',"Img_url","link");
$crud->class_add_field($fieldForm,'form-control');
$crud->class_edit_field($fieldForm,'form-control');
$crud->class_add_field('Title','form-control span10');

$crud->class_add_field('Title','form-control span10');

$crud->attribut_add_field('Title','readonly required="required" ');
we'll have 
<input type="text" maxlength="500" readonly="" required="required" value="" name="Title" class="form-control span10" id="field-Title">

$crud->attribut_add_field($fieldForm,'required="required"');