Attributes for CAS 2

Hi Chris,
I'd love some feedback and/or code review for this patch.

I'm not a fan of SAML, so I've added a simple extension to CAS 2. The ticket validation includes:
<attributes>
    <uuid>1234-5678-90</uuid>
    ...
</attributes>

mod_auth_cas stores this into the CAS Cache Entry.
mod_auth_cas sets it into the sub-process environment as CAS_KEY so 
CAS_UUID=1234-5678-90 would be readable as a CGI ENV variable.

I'm a C newbie, so a code review would be appreciated!

Thanks,
austin