[Tinyos Core WG] T2 Release

[Prabal Dutta]

The following has been certified by David Gay to be insanity-free:
- Lesson 7
- apps/tutorials/BlinkConfig
- apps/tutorials/PacketParrot

One other note: The T2 downloads page has a link to only one version
of the nescc Cygwin tools.  Perhaps we should add the following link
for people with the "other" Cygwin version:

http://www.tinyos.net/dist-1.2.0/tinyos/windows/nesc-1.2.8b-1.cygwin.i386.rpm

- Prabal