Add error handling to createStorageMasterKeyWithPassword
and update unit tests
Add error handling to other master key methods
update unit tests
Rename masterKeyError to storageKeyError
improve error handling in all DBs
Add error handling to getter methods for user keys DB
Rename TSEncryptedDatabaseError to TSStorageError
Move storage unit tests to a storage group
Add documentation to TSStorageMasterKey
Add documentation to TSEncryptedDatabase
clarify comments
Address remaining TODOs in TSEncryptedDB unit tests MONEYMONEY
Merge branch 'master' of https://github.com/nabla-c0d3/TextSecure-iOS into nabla-c0d3-master