Removed unsuccessful fix for #1982.

Will be fixed in Simperium instead.
Mark note as read only if it is unread.
Synchronizing access to Note JSONObject instance

Protects from concurrency exceptions when reading and modifying the JSON values.

see #1982
Updating to Simperium 0.6.0

Includes Concurrency fixes.
Synchronizing on final object
Explicitly set Simperium version

Remove @aar, it was excluding the dependencies from being included.
Fixed a crash that could occur if `mNoteBlockArray` was modified in the background.

Adapter data shouldn't be modified in the background, so I removed the instance variable.
Merge branch 'release/3.4' into issue/1982-simperium-concurrency
Conflicts:
	WordPress/src/main/java/org/wordpress/android/models/Note.java
Merge pull request #2004 from wordpress-mobile/issue/1982-simperium-concurrency

Thread safety for Note class