Build scripts

Resent, based on #38 
You need to open the `.sublime-project` file as a project in ST. You do that by passing the file to `subl.exe` on the cmdline or by opening the file via **Project | Open Project...**. The *Run* build system will only be active when the *PowerShell.sublime-project* file is in use.

Also, it seems that you have multiple Powershell build systems listed there. If you still have the repo under Packages, there may be conflicts.