AVR Dragon - solid enclosure

Enclosure for AVR Dragon programmer and debugger.

Design notes:
* The enclosure should not press any components mounted on the Dragons PCB; there are separators (placed on the top part of the enclosure) to ensure that the ferm contact stays only between enclosure and PCB;
* Allows space for connecting IDC cables, not just jumper wires;
* The foam from the original package can be used to safely secure the PCB inside the enclosure without directly applying presure to the board when tighte