Move X cookie generation out of Session code.
Do not generate an cookie as root when loading

It's not used by anything
Remove explicit delete call to parented object

d->socket has the GreeterProxy object as a parent so will be deleted
anyway
Proxy messages from the greeter in SDDM output
Catch errors launching the greeter before we block.
Move generateName to a separate file
SocketServer generates it's own name

SocketServer is in charge of creating the socket name. It then exposes
the full socket path.

SocketServer is changed to not have m_started and the server in separate
states.
Only set session environment user/path if set
Use vt 1 when systemd support is available

systemd graphical mode uses vt 1 for display managers.
Add missing USE_PAM definition to Authenticator.cpp
Always go via PAM for autologin

This passes our session through the systemd PAM module that sets up
logind correctly, fixing a bug where polkit actions would not work
correctly in an SDDM session
Provide seat name and virtual terminal number to PAM environment variables
remove pointless pam checks in autologin
Merge pull request #168 from w41l/master

Add missing USE_PAM to Authenticator.cpp
Merge pull request #142 from davidedmundson/fix_autologin

Fix Polkit sessions with autologin
Merge pull request #167 from plfiorini/systemd

Use vt 1 when systemd support is available
Start the greeter under the user sddm
Merge pull request #159 from davidedmundson/nonrootgreeter

Don't run the greeter as root
Set use rpath
Quote all CMake path arguments

Fixes #111