Good way to get automatically generated code into a sketch
According to the release notes starting with V1.5.2 of the IDE you can verify and upload from the command line.

You could use your favorite editor and then use the command line to do the arduino build/upload instead of the IDE.

See: https://github.com/arduino/Arduino/blob/ide-1.5.x/build/shared/manpage.adoc

I have not used it so I can't say if it work well or not.