added custom growl and file watcher integration

I've added a custom file watcher script for you to help with coding.  Here is some info:

Rakefile.rb: this is where you can start placing build automation tasks, there are currently to commands.

    rake #this will build your solution
    rake tests #this will run the nspec tests

dotnet.watchr.rb: this is where the file watcher logic is, line 54 is where you'll want to start reading.  Basically it runs the default `rake` task and parses the output using regex.  If the build succeeded, then it runs the `rake test` command and parses that output to see if there are any failures.