Detect missing options earlier, without bothering master.

Also, s/isSlave/slave/ .
Also, when doc says we default to "false", literaly default to "false".

Signed-off-by: Cédric de Saint Martin <cedric.dsm@tiolive.com>

User (with enough privileges) must be supplied, otherwise logs are never
reopened.
Also, quote socket and binary paths.

Conflicts:
	component/rpm2cpio/buildout.cfg
	component/slapos/buildout.cfg
	setup.py
	slapos/recipe/6tunnel/__init__.py
	slapos/recipe/request.py
	stack/slapos.cfg