Add a SimpleBind function that will use a SimpleBindRequest and will return a
SimpleBindResult (also on error).
This function will let the user to add additional Ldap Controls on the bind request and to get
additional ldap Controls on bind response. This is needed to request and get additional password
policies informations.
Add password policy Controls as described in draft
(https://tools.ietf.org/html/draft-behera-ldap-password-policy-10)

This is the method used by openldap. Other ldaps like the netscape ldap
derivatives use another draft
(https://tools.ietf.org/html/draft-vchu-ldap-pwd-policy-00).
Add an example of usage of Behera Password Policy Controls.
Merge pull request #1 from sgotti/beherappolicy

Add support for Password policies as described in https://tools.ietf.org/html/draft-behera-ldap-password-policy-10