even for sighted users

linked label where possible

added "no-css" class to overwrite the current label style

added invisible label

For ChiliProject 3.0 we will strictly require rmagick >= 2.0. If you need it,
you might have to update your distribution or install ImageMagick from
alternative sources.

There's a hint in the Gemfile for people with older distress.

Prevent large production databases from consuming all the RAM on the server
and causing the migration to take forever. With this patch, objects are read
in batches from the database. This removes the need to hold ruby
objects for all rows for a type in memory at once.