Windows DCs return an empty reply when a legal request cannot satisfied.
If we get EINVAL or ENOENT it means the information requested could not be
found or input parameters were bogus.
Always return an empty reply in these cases.

On any other internal error just return, the request may have been legit but we
can't really handle it right now, pretend we never saw it and hope the next
attempt will succeed.

Fixes: https://fedorahosted.org/freeipa/ticket/3639

Signed-off-by: Simo Sorce <simo@redhat.com>

1. Stop using getdomainname() as it is often not properly initialized
2. The code using getdomainname() was not working anyway it was trying to
look at the function call output in hostname which is always empty at that
point.
3. Always check the requested domain matches our own, we cannot reply to
anything else anyway.

Pre-requisite to fix: https://fedorahosted.org/freeipa/ticket/3639

Signed-off-by: Simo Sorce <simo@redhat.com>

Insure user accounts are valid and the password is not expired
before allowing a password bind.

TODO: handle returning a control with more detailed information about
failures (only if explicitly requested by client)

During LDAP bind, this now plugin determines if a user is enabled
for OTP authentication. If so, then the OTP is validated in addition
to the password. This allows 2FA during user binds.

    https://fedorahosted.org/freeipa/ticket/3367
    http://freeipa.org/page/V3/OTP

https://fedorahosted.org/freeipa/ticket/3596

https://fedorahosted.org/freeipa/ticket/3596

Request with a SID as input parameter do not contain the domain name,
hence is must be tried to resolve the SID first before the corresponding
domain can be looked up.

https://fedorahosted.org/freeipa/ticket/3596

https://fedorahosted.org/freeipa/ticket/3539

Fix rpm build warnings report in Fedora 19 build.

https://fedorahosted.org/freeipa/ticket/3500