Use sssd for authentication and user information
Extend sssd changes to unset-network
Properly unjoin in unset-network for Samba4 domains
Update sssd to 1.9.6 through PPA, to use default_shell option
Modify install procedure for sssd
Add logging logic to install
Affect sss-password PAM config along with sss config
Add alternative PAM config sss-password, modify install to cope

install.sh now installs configuration before doing users, so that PAM modules
can be correctly configured before PAM is used to change passwords etc. Any
PAM modules found in `configuration` are removed prior to being copied across
to ensure a clean state
Fix logic with guessing PDC
Add nscd to install list to prevent autoremove from removing it
Tweak nscd invalidation to remove unnecessary calls
Remove DPKG firewall rule generation hook

Repeatedly regenerating the firewall rules is going to play havok with any
network access during that time - it is best just to require a restart to get
new services to work
Remove unnecessary bleachbit from install list
Modify points at which network settings are set

The hostname must be correct before a domain join is attempted
Use default Google nameservers if SERVERIP not set
Fix permissions and LDAP base in sssd.conf
Close progress window on cancellation
Merge branch 'sssd', closes #31

Conflicts:
	linuxclientsetup/config-files/samba4/etc/samba/smb.conf