Auto set the release stage

Set the release stage to dev if we are compiled with DEBUG on, or if the
debugger is attached - else default to production.
Yeah not testing it is obviously fine - I was just wondering how stripped a .NET binary could be - I know they output [pdb files](http://www.wintellect.com/blogs/jrobbins/pdb-files-what-every-developer-must-know) but I haven't yet worked out what information is removed from the binary and put into the PDB file. I see filenames in there so I was guessing that filenames might not appear in the stacktrace in a fully optimised app.