This commits adds 2 things:
 - Returns a JSON object if the json parameter is defined in the URL (example: http://<ip>:<port>/?json,
   http://<ip>:<port>/processes?node=localhost&json)
    - 'page' and 'is_xhr' are not return in the JSON object (not needed)
    - I added the field 'timestamp' to the JSON object (it contains the timestamp of the response).
 - Add http://<ip>:<port>/process/<pid>/all, it returns a JSON object which contains all sections (Overview,
   Environment, Threads, Open files, Connections, Memory maps, Children, Limits)