improve time between test runs

[briancherne]

EnvJasmine is AWESOME! The Maven integration is great! However, each run takes ~5 seconds to load Rhino w/Envjs. I'm trying to get into a rhythm of testing every change and the ~5 second delay is non-optimal . I'm not sure what the simplest/best solution is, but it seems like it might be possible to run Rhino in an interactive mode, so all a developer needs to do (in this mode) is re-run test script(s). Ideally we could preserve the awesomeness of command line unit tests and improve the time between manually executed test runs.