Changing underlying storage of keys to SFKeyStoreKey, to denote classes
Moving key store out into its own classes
Interim checkin: lots of key store class implementation
Some workflow bugs / errors found at initial runtime pass
Moving passcode verification before creation/update
Delegating responsibility of passcode startup validation to SFSecurityLockout
Misc updates, comments for key store functionality
Clarifying clearPasscodeState and clearAllPasscodeState usage
Fixing typo in comments
Merge pull request #588 from khawkins/keystore_key_classes

Key store key classes
Merge branch 'unstable' of github.com:forcedotcom/SalesforceMobileSDK-iOS into unstable23merge