allow for running with rails server

allow for running with rails server, makes development on mac possible without having to install full apache stack with ruby.
For me, this turned off generation of schema.rb during migration but didn't turn on generation of development_structure.sql.  To generate that, I have to run `rake db:structure:dump`.  Or it also gets (re-)generated if I clone the development database structure to the test database using `rake db:test:clone_structure`.

In any case, I don't see any reason for this to go here rather than in config/application.rb.