Merge pull request #15784 from sgrif/sg-delimiter

Ensure `OID::Array#type_cast_for_database` matches PG's quoting behavior
Add a generic --skip-gems options to generator

Also remove --skip-turbolinks.

This option is useful if users want to remove some gems like jbuilder,
turbolinks, coffee-rails, etc that don't have specific options on the
generator.

    rails new my_app --skip-gems turbolinks coffee-rails
:scissors:
initialize the right variable
Detect mutations of arrays and array members