Is it possible to configure LDAP and LDAPS through the LDAP_URI. The variables could then be simplified too

``` yaml
graphite_ldap_enabled: False
graphite_ldap_uri: ldap://ldap.mycompany.com:389 # or ldaps://ldap.mycompany.com:636
graphite_ldap_search_base: "OU=users,DC=mycompany,DC=com"
graphite_ldap_base_user: "CN=some_readonly_account,DC=mycompany,DC=com"
graphite_ldap_base_pass: "readonly_account_password"
graphite_ldap_user_query: "(username=%s)"
```