This will make possible to do a frameworkless initialization since the the default middleware stack is self contained.
This behaves similarly to REQUEST_URI, but we need to implement it on our own because REQUEST_URI is not reliable. Note that since PATH_INFO does not contain information about trailing question mark, this is not 100% accurate, for example `/foo?` will result in `/foo` in ORIGINAL_FULLPATH
Conflicts: railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt railties/test/generators/app_generator_test.rb
… to use a global gitignore. Remove .sass-cache since we use /tmp/sass-cache, which is already ignored.