Prepare RFID compilation in firmware mode

- switch from linked lists to static arrays
- remove all non-handle dynamic allocations (at the expense of stack)
- declare all proto/reader/asic/layer2 structures as const
- wrap all handle allocations in macros that expand to references to
  static structures in case of firmware mode
- update copyright notices
- add skeleton code for openpcd-inside-firmware driver
- update TODO with remaining TODO for firmware mode

git-svn-id: https://svn.gnumonks.org/trunk/librfid@1903 e0336214-984f-0b4b-a45f-81c69e1f0ede