New specification

Adds new features:
- [x] Isolated validation (partial verif.) now supports multiple iterations
- [x] Secret recombination also supports multiple iterations. The value is set to be lower than expected since tests timeout (they are pretty intensive in the C version).
- [x] Alarms are raised when isolated validation passes but the whole hash doesn't
- [x] Bootstrap account creation is now possible.
- [x] Bootstrap accounts are updated to shielded accounts upon successful recombination

Terminology updates:
- [x] partial verification -> isolated validation
- [x] partial bytes -> isolated-check bits
- [x] lock/unlock -> bootstrap
- [x] threshold account -> protector account
- [x] thresholdless account -> shielded account.