vct: update server version and silently keep /tmp/pip-trash
confine/*.lua: accept is_admin=true and is_technican=false as node admin and add authorized keys
vct/server: import from devel_settings instead of production_settings
vct: update VCT_SERVER_VERSION='0.8a29'
vct/server: specify preliminary fixtures/vcttemplates.json
vct preinstall default templates and exp_data
update VCT_SERVER_VERSION='0.8a30'
vct preinstall default slices via fixtures/vctslices.json
confine/*.lua more node RestApi fixes