SW-96. Use webapp mesh debug export state to set Export packets checkbox.

Removed use of unnecessary client cookie.
Also cleaned up Ajax error reporting.
SW-96. Always include mesh debug export state and event list.

Include event list with initial page display to prevent unnecessary initial
AJAX call. Include mesh debug export state with AJAX to ensure checkbox
matches ongoing state on server.
Also cleaned up response methods in openVisualizerWeb.
Merge pull request #49 from kb2ma/SW-96b

SW-96. Make export packets checkbox consistent with application state