Better Organization for Ds2411 Chip and Epic

These commits do three things:

1. Update the ds2411 code to have more intuitive variable names. Basically I got rid of all things Dallas in the code.
2. Factor out the specific pin used for the ds2411 to an Hpl file in `platforms/epic/chips/ds2411`.
3. Move the code to more logical places in the tinyos tree. Putting everything in a platform specific chips folder doesn't make any sense, and the 11 files there were confusing.