stop converting strings to symbols
reduce the number of queries on IN clauses, fix relation queries in `where`
don't need to eval everything
module_eval is not necessary here
use the helpers list rather than getting the methods from the module
Deprecate the `eager_load_paths` configuration

Since the default in Rails 4.0 is to run in 'threadsafe' mode we need
to eager load all of the paths in `autoload_paths` so we alias
`eager_load_paths` to it. This may have unintended consequences if
you have added 'lib' to `autoload_paths` such as loading unneeded
code or code intended only for development and/or test environments.
If this applies to your application you should thoroughly check what
is being eager loaded.
Remove obsolete test file

https://github.com/rails/rails/commit/4beb4dececcf10c642c74fbcb8548c833e921a86#commitcomment-2482869