This is more for development. While you're developing a plugin, you can symlink it to the `~/.mortar/plugins` directory and the mortar plugin won't mess with it. 

I personally don't use this, instead when i'm developing a plugin, I have a Rake file that watches the directory and RSyncs to the `~/.mortar/plugins`. 

Once again, this code came from the Heroku gem, I think keeping it will keep things familiar for anyone that's written a Heroku plugin, but I could be swayed. What're your thoughts?