add JSON
Update README.md

iOS7 JSONKit support note.
Update README.md
Update README.md
Added feature:
* added additional method which allow to change client identifier and catchup on subscribed channels
* copied library into demo projects
* updated library information (debug output in console)
Enhancements:
* tweaked client identifier logic change in a way, which will allow to send all presence events and still be able to catchup
* copied library into demo projects
* updated library information (debug output in console)
Fixed issue:
* fixed wrong state flag which prevented catchup to go in correct way

Tweaked:
* added proper handling of error, which may occur during client identifier update
* copied library into demo projects
* updated library information (debug output in console)
Merge branch 'origin/feature-t181'
copy test from branch 3.5.2_test
add path
update UI