Permissions overhaul - Define permissions in the database

2nd attempt at this one!
Similar to #1008 but separately defining the roles, modules and associated permissions in the database.
Also has admin being a defined role automatically having full access.

Parent issue: #530

admin_roles.php

@@ -45,11 +45,6 @@ $num_rows = mysqli_fetch_row(mysqli_query($mysqli, "SELECT FOUND_ROWS()"));
                             </div>
                         </div>
                     </div>
-                    <div class="col-md-8">
-                        <div class="float-right">
-                            <!--<button type="button" class="btn btn-default" data-toggle="modal" data-target="#exportRoleModal"><i class="fa fa-fw fa-download mr-2"></i>Export</button>-->
-                        </div>
-                    </div>
                 </div>
             </form>
             <hr>

functions.php

@@ -1356,13 +1356,13 @@ function lookupUserPermission($module) {
         $mysqli,
         "SELECT 
 			urp.user_role_permission_level
-		FROM 
+		FROM
 			modules AS m
-		JOIN 
+		JOIN
 			user_role_permissions AS urp
-		ON 
+		ON
 			m.module_id = urp.module_id
-		WHERE 
+		WHERE
 			m.module_name = '$module' AND urp.user_role_id = $session_user_role"
     );