We now automatically move non-rt clients into non-rt threads so the
client-rt.conf is obsolete.
Move the module-rt in client.conf and add conditions to disable modules.
Transparently load client.conf in case applications still specify
client-rt.conf.
Custon configuration in the client-rt.conf.d/ should be moved to
client.conf.d/
Whe using pw_*_new_simple(), pass the properties to the automatically
created context as well so that we can configure it.
This makes it possible to, for example, load the client-rf.conf using the
simple API as well.