Rewritter puavo-ltsp-login to support multiple servers in DNS SRV
records, ldap slave servers and simple binds in addition to SASL
GSSAPI connections. Makes it possible to use puavo-ltsp-login on
laptops.
Support for LDAP slave connections behind VPN. Also limit the number of
USR2 signals sent to sssd.
Cleanup the configuration process a bit and make it more resilient to
errors.