Support for non-IDEA IDEs

This adds support for non-IDEA IDEs.

For anyone that's interested in testing this, please get [non-IDEA google-go-language.jar](https://www.dropbox.com/sh/kzcmavr2cmqqdqw/j8wjp8SdNH) from my Dropbox. Thank you!

Note: I'm only testing this with PHPStorm 7.1 EAP.
Note2: Support for importing existing projects is not there yet (workaround: create the project in a new folder and then overwrite the sources with your current sources).