fix #1981: catch OOM exceptions around mixpanel _People_ write access
Set getDiffableValue() as synchronized in the Note model.

Fixes #1982
No need for AndroidAsync snapshot any longer.

AndroidAsync released an update, and Simperium 0.4.12 will use it.
Return a copy of the JSONObject in getDiffableValue().
Adding JSONUtilTest
Merge pull request #1990 from wordpress-mobile/issue/1982-simperium-concurrency-exception

Fix Simperium concurrency exception
Merge pull request #1986 from wordpress-mobile/issue/1981-oom-mixpanel

fix #1981: catch OOM exceptions around mixpanel _People_ write access
3.3.1 version bump
Merge branch 'hotfix/3.3.1' into release/3.4

Conflicts:
	WordPress/build.gradle
Merge branch 'release/3.4' into develop