DataSpace Sync Client Release 2.0.0

Complete new sync architecture:
* Event based synchronization
 * File system events are used to publish client side changes to server
 * CMIS ContentChanges are used to react on server side changes
 * Minimized full directory crawling
 * Changed from SQLite to DBreeze key/value store
 * Synchronization is acting on file/folder objects, not on paths
* Enhanced file/folder move/rename detection via extended attributes
* Creation and modification date synchronization
* Supports server side SHA-1 hashes to detect equal content and reduce retransmissions of equal content
* Reduced connection retries on wrong user credentials

And a lot of bugfixes
Merge branch 'master' into develop