How to grant permission directly to a user other than a role?

Question

Our client frequently need to grant arbitrary permissions to arbitrary users. It's very boring and fault-prone for our client to create new roles, assign users to roles and then set role permissions.
The module user permissions can grant permissions directly to a user, but the grantee must have the powerful permission "administer permissions", which is not what I want.

Answer 1

Use the user permissions module. Contrary to your objections to using this module, it is not the grantee who needs the "administer permissions", but the grantor

Answer 2

Create role:

if (!user_role_load_by_name('new_role')) {
  $role = new stdClass();
  $role->name = 'new_role';
  user_role_save($role);
}

Add Permissions:

$new_role = user_role_load_by_name('new_role');
$values[] = array(
  'rid' => $new_role->rid,
  'permission' => 'create article content',
  'module' => 'modulename'
);
$query = db_insert('role_permission')->fields(
  array(
    'rid',
    'permission',
    'module'
  ));
foreach ($values as $record) {
  $query->values($record);
}
$query->execute();