please add get_role_by_name

i'm wondering why there is no function like get_role_by_name()

when you add a role in drupal, you define a name, not a $id => $name, so the name should be used to identify a role

my goal is to use user_has_role() with the name of the role i want to check for, i don't want to look up the $rid for the role name or even hardcode it