Upgrade to Rails 4.0 -- initial phase
Upgrade to Rails 4.0 WIP
Use association names instead of SQL in 'joins'

Use association name symbols instead of string SQL in 'joins' for defining scopes.  I have not debugged it, but it seems Rails 4.0 stopped working in some cases with SQL strings in 'joins' method.
Use 'includes' for LEFT JOIN for Rails 4

Rails 4 does not seem to accept string SQL conditions for 'joins' method.  Use 'includes' with the new API.
Adjust custom form builder to Rails 4 - WIP
Do not use symbols as params keys
Implement more params processing
Small simplification in UserController#update