Feature/export

Hi, @Tyilo. You've been a great help in the development of Play Song, and so I feel compelled to ask for your feedback once again (because, of course, I value your input).

After much investigation, I've discovered a way to automate the process of exporting the Play Song workflow. I've crafted a Bash script which does the following:

1. Copies the latest `Configuration.applescript` and `compile.sh` to the installed workflow
2. Zips together the files in the installed workflow (excluding the compiled `Configuration.scpt`)
3. Converts the newly-created zip file to an `.alfredworkflow` file in the project repository

What do you think? :D