dol: initial epiphany code generator (untested)

First shot of a DOL code generator for Epiphany.
Our Epiphany currently does not have access to the internet.

notes:
- all communication channels in shared memory (slow)
- no architecture specification used (hard-coded for our board)
- no manual mapping possible (processes are placed left-right, top-bottom)
- no usable input/output to the processes possible
- completely untested!