removed field accounts from class Account as the removal of this bidirectional association has been missed
removed SerializedName annotations, unneeded import and trailing whitespace from Contact class
removed unneeded imports in ContactTypeAdapter
added todo in write() method of ContactTypeAdapter
removed unneeded @SerializedName annotations and import in class SyncedSettings
removed unneeded imports in class SyncedSettingsTypeAdapter
Modified: CryptoUtils is not a singleton anymore

This avoids multi threading issues.
Key related methods were moved to the QblKeyFactory singleton class.
added json field name to javadoc of serialized fields in class Contact
added json field name to javadoc of serialized fields in class SyncedSettings
added json field name to javadoc of serialized fields in class Account
added json field name to javadoc of serialized fields in class DropServer
added json field name to javadoc of serialized fields in class Identity
added json field name to javadoc of serialized fields in class LocalSettings
added json field name to javadoc of serialized fields in class StorageServer
added json field name to javadoc of serialized fields in class StorageVolume
Merge pull request #203 from f-porter/Issue-202-Remove-unneeded-and-wrong-parts-in-config

Issue 202 remove unneeded and wrong parts in config
changed json field type of field "data" in serialized drop message from JsonString to JsonObject
Merge pull request #208 from f-porter/Fix-Issue194-Wrong-type-of-data-field-in-drop-message

changed json field type of field "data" in serialized drop message from ...
Changed QKF methods using CryptoUtils to synchronized
Merge pull request #205 from L-Henke/nonSingletonCryptoUtils

Modified: CryptoUtils is not a singleton anymore