various

1.  Added solution folder for tests
2.  partial rename to unit tests project
3.  Made Scale.cs properties private and changed init via constructor
only
4.  Reworked Scale.cs toString which was implemented haphazardly
5.  Reworked Temperature.cs toString which was implemented haphazardly
6.  Updated NUnit to 2.6.3
7.  Deleted unused App.Config in GUI project
all