Add support for password hash attributes

[tcsalameh]

This adds two attributes used to specify the how LDAP hashes passwords.
password_hash sets the type of hash that the LDAP server will use, while
password_crypt_salt_format sets the format of the salt.

[coveralls]

Coverage decreased (-0.4%) to 55.0% when pulling ae1e3cc on tcsalameh:pw-hash into 0cb2567 on bodgit:master.

[coveralls]

Coverage decreased (-0.4%) to 55.0% when pulling ae1e3cc on tcsalameh:pw-hash into 0cb2567 on bodgit:master.

[bodgit]

Cool, I'll commit this with a few tweaks. Notably I recently found these additional password mechanisms so I'll amend the regex to handle these.

[tcsalameh]

Thanks! I didn't know that OpenLDAP supported those additional mechanisms, good to know.

[bodgit]

They are however, a bit of a PITA to build. You basically need to have the full OpenLDAP source unpacked and ./configure'd before you can build them. I was looking at how easy it would be to build some packages for these extra password modules and it looks like I'd have to duplicate most of the RPM spec.

[bodgit]

I managed to get SHA2 support built and tested so I've added some additional parameters that allow you to pull in additional packages for non-standard hashing schemes.