use anti_spam plugin in suggest_articles

ActionItem2691
README: provide a documentation index
COPYRIGHT: update copyright notice for Colivre
Remove obsolete HACKING instructions
script/development: fail on pending migrations
HACKING: point to contributor doc on the wiki

At some point that documentation should be moved to the source
repository.
Merge branch 'doc' of /mnt/ebs/repositories/terceiro/noosfero
Right database.yml update on quick-start script

Closes ActionItem2856
Merge remote-tracking branch 'lucasmelo/spam' into lucas-spam
anti_spam_plugin: refactor wrappers logic
spammable: encapsulate the spam logic to a module
spammable_hot_spot: encapsulating spammable hot_spots
spammable: fail safe measures

   * Avoiding module inclusion on models that doesn't have a spam
     attribute.
   * Avoiding named_scope filters on models that doesn't have
     named_scope.
manage-spam: show only tabs that has spam
schema: remove mistakenly added plugins tables
Merge commit 'refs/merge-requests/405' of git://gitorious.org/noosfero/noosfero into merge-requests/405
Merge branch 'AI2823-video_plugin' of github.com:fga-unb/noosfero into AI2823-video_plugin
Merge merger-request:
https://gitorious.org/noosfero/noosfero/merge_requests/406
Update Authors