[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.
option_group_changed('port', 'main', 'web')
option_group_changed('query-log-file', 'main', 'web')
option_group_changed('profile', 'main', 'web')
option_group_changed('max-post-length', 'main', 'web')