Name change: Partial Bytes -> Isolated-check bits
Adds support for bootstrap accounts
Adds recombination iterations
Adds iterations for the ICB settings
Fixes bug in bootstrap account updating

When updating bootstrap accounts, the sharenumber field wasn't updated
(it needed to change from -1 to 0) in the previous versions
Increases the default value for recombination iterations
Thresholdless -> shielded
Threshold account -> protector account
Stores the secret integrity check as a separate field...
updates to new version of the paper
Merge pull request #4 from PolyPasswordHasher/new_specification

New specification