Add compiler plugin continuation to project settings

I have today made a fork and implemented a solution for adding continuation compiler plugin to idea config. See bug https://github.com/mpeltonen/sbt-idea/issues/102

Only problem is that I am not sure the path is calculated the correct way or if I somehow could get access to the "addCompilerPlugin" lib defined in the build. The above solution works for me on linux.

Do you see any problems including this in please let me know and I will try solving it