Added a bullet point there showing how the Uninitialized Constant
(missing migration class) error looks like.

ActiveModel::Observer and ActiveRecord::Observer have similar
documentation, but a Rails user looking at the ActiveModel version
might not realize that a change to config/application.rb is
required to activate the observer. This change adds a note to
that effect, pointing to the AR version from the AM version.

Reason: Calling docrails a "branch" is fine, no need to change the terminology. It is a remote in my machine, and it has been called branch since the very beginning: http://weblog.rubyonrails.org/2008/5/2/help-improve-rails-documentation-on-git-branch

This reverts commit 35a266ed.

change plugins guide to favor gem based plugins, clean up to reflect the state of Rails3 plugins, remove information not compatible with Rails3.

Revert "Add note about running `bundle install` as root. Solves issue with '#' not being rendered, and it's more clear for beginners."

Reason: Running bundle as root is not recommended.

This reverts commit 0d40e2c3.

Add note about running `bundle install` as root. Solves issue with '#' not being rendered, and it's more clear for beginners.

Change ActiveRecord::Base.xyz to config.active_record.xyz in docs.

Remove <tt> from code samples.

Update skip_time_zone_conversion_for_attributes code sample: put the call in the model class.

Clarify that skip_time_zone_conversion_for_attributes skips converion when reading.