consoleexport support the feature for saving as JSON file

[EvanHon]

Now, consoleexport can only be exported as HTML file which is not convenient for me to extract useful data.
Need to support export as json file.

[EvanHon]

For details see the following link : https://groups.google.com/forum/?fromgroups#!topic/firebug/BtB8n3kKM1w