This reverts commit 6909fe3b.

buildout can be run and may need libnetworkcache in order to run tests (if zc.buildout.testing.buildoutSetUp() is called).

also add a temporary patch to respect more tokens in natural language mode.

Move dcron test in dedicated directory/file.
Also move slapos/recipe/test to slapos/test.
Currently : only dcron test.

Conflicts:
	software/slaprunner/schema.json
	software/slaprunner/software.cfg.json

also use the explicit version of nginx-dav-ext-module.
also remove too old nginx-unstable.