Update spec and implementation to version 3.0.
- Add version 3.0 of the specification document, under /spec.
- Version 3.0 replaces pincic2-* with picnic3-* and adds three new
parameter sets, picnic-*-full. Details of picnic3 are in the paper
spec/picnic3-eprint.pdf - Update implementation to match version 3.0 of the spec.
- Update design document to version 2.2, with updated QROM analysis
based on the work of Don, Fehr, Majenz and Schaffner (see ePrint
2019/190)