[debian] build the book with no auto-compression of book files (closes: #1906581)
Book content paths (html and rest) are now excluded from Debian compression step.
This will fix a documentation search issue on the website (doc.cubicweb.org)
Documentation build is now made optional since it can break for old distributions
and we don't want to block a new release of Cubicweb because of documentation issues.
First of all, you can use this site as any web site by clicking on the
different links. The Logo on the top left of this page will lead you
to a start page from which you will be able to navigate to all the
data hosted on this site.
The bookmarks box on the left hand side provides some useful
shortcuts.
Most text is indexed and you can search all the content by typing
words in the search box.