Added signature to encrypted messages.
Changed visibilities of methods in CryptoUtils.
Added log messages for (currently) unhandled exceptions.
Fixed usage of wrong RSAPrivateKey in CryptoUtils rsaSign()
Fixed sub-key signing. Changed method named in CryptoUtils
Fixed CryptoUtils rsa sign fix again
Changed CryptoUtils logger to final static
Merge pull request #59 from L-Henke/cryptoImprovement

Added signature to encrypted messages and CryptoUtils improvement.
Added Bouncy Castle cryptographic provider to build.gradle
Switched cryptographic provider to Bouncy Castle
Switched RSA signing algorithm to RSASSA-PSS
Merge pull request #63 from L-Henke/bouncyCastle

Added Bouncy Castle cryptographic provider to build.gradle
Changed rsaSign() parameter name from 'message' to 'data' to avoid confusion
Changed rsaSign() Javadoc description.
Renamed encryptHybrid() to encryptHybridAndSign() and
decryptHybrid() to decryptHybridAndValidateSignature() because encryption
and signing are indepented operations. This should be expressed by the
method name.
Merge pull request #62 from L-Henke/cryptoImprovement

Changed rsaSign() parameter name from 'message' to 'data'
moved class fields to top of class and added new constructors in classes:
* Account
* DropServer
* Identity
* LocalSettings
* StorageServer
* StorageVolume
* SyncedSettings
new classes:
* AccountsTypeAdapter
* ContactsTypeAdapter
* DropServersTypeAdapter
* IdentitiesTypeAdapter
* StorageServersTypeAdapter
* StorageVolumesTypeAdapter
added hashCode() and equals() methods to following classes:
* Account
* Accounts
* Contact
* Contacts
* DropServer
* DropServers
* Identity
* Identities
* LocalSettings
* StorageServer
* StorageServers
* StorageVolume
* StorageVolumes
* SyncedModuleSettings
* SyncedSettings
added test for config serialization
Catch org.bouncycastle.crypto.DataLengthException in rsaDecrypt()
Merge pull request #65 from L-Henke/dataLengthException

Catch org.bouncycastle.crypto.DataLengthException in rsaDecrypt()
* added "@SerializedName" annotations to match the documentation
* renamed field "lastUpdate" in LocalSettings to "dropLastUpdate"
* removed unneeded import in ConfigSerializationTest
Merge pull request #64 from f-porter/Issue33-Config-Serialization

Fixes #33 config serialization
First draft for DropHTTP