[c-c newcube] #1192: simpler cubicweb-ctl newcube, and more
* new --layout option, to get 'simple' or 'full' cube
* new --licence option to specify license for the cube
* added README and sobjects.py template (the later only added in full layout)
* fixed python file templates to get proper headers according to the config
"""%(distname)s precreate script, executed at instance creation time or when
the cube is added to an existing instance, before the schema is serialized.
This is typically to create groups referenced by the cube'schema.
:organization: %(author)s
:copyright: %(year)s %(author)s
:contact: %(author-web-site)s -- mailto:%(author-email)s
:license: %(long-license)s
"""