- coord solver
  - add new parameter to solve(): options (char *)
    - fix all usages
      x tests
      x shell
      - tools
      - python bindings
      - document what to do when changing interface?
    - where do I document which solvers take which parameters?
      now that I am implementing more solvers I need an extra
      document in doc/
  - in nissy.c, check for minmoves, maxmoves and nissflag (must be in range)
  - add a dispatcher in solvers.h?
- test solver for EO
- add NISS (and add tests for NISS EO)
- make solve parallelized
- other coordinates
  - gendata must handle symmetry
- make gendata parallelized

- refactor common parts of coord and h48 solvers
- move parse_h48 to h48 module?