[book] some more documentation and cleanups
* merged existing facets documentation with the one I've just written and
put almost everything within the code
* added a note about __depends__ and __recommends__ and about the recommends
semantic (extracted from a post on the ml)
* added a note about write security checking (extracted from a post on the ml)
* fixed some dumb sphinx errors
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s schema"""