Added a data export option to export JSON representation of objects (e.g. _EPROCESS).

Data is exported into JSON (or a python dict). The format is similar to the JsonRenderer:

1. The output consists of a series of  lists.
2. The first item in each list is a command:
   "m": Tool metadata
   "t": Define the table headers for tools which want to display the original table format.
   "p": A progress indication for interactive tools.
   "r": A table row - this is a simple dict with keys being the headers of each column. The values are specifically encoded for the type of data. For example, for _EPROCESS we also encode a Cybox like object (This is still JSON though not XML).

Here is an example:
[
      "r",
      {
         "session_id" : 0,
         "wow64" : false,
         "thread_count" : 8,
         "_EPROCESS" : {
            "vm" : "IA32PagedMemory@0x00039000 (Kernel AS@0x39000)",
            "type_name" : "_EPROCESS",
            "name" : "_EPROCESS",
            "Cybox" : {
               "Image_Info" : {
                  "Path" : "C:\\WINDOWS\\system32\\wuauclt.exe",
                  "File_Name" : "\\Device\\HarddiskVolume1\\WINDOWS\\system32\\wuauclt.exe",
                  "type" : "ProcessObj:ImageInfoType",
                  "Command_Line" : "\"C:\\WINDOWS\\system32\\wuauclt.exe\" /RunStoreAsComServer Local\\[43c]SUSDS82f0c54ad7b58b46a717b19ec999e73f"
               },
               "PID" : 3984,
               "Parent_PID" : 1084,
               "Creation_Time" : {
                  "type_name" : "UnixTimeStamp",
                  "value" : 1284061965,
                  "string_value" : "2010-09-09 19:52:45+0000"
               },
               "type" : "ProcessObj:ProcessObjectType",
               "Name" : "wuauclt.exe"
            },
            "offset" : 2179642104
         },
         "process_create_time" : {
            "type_name" : "UnixTimeStamp",
            "value" : 1284061965,
            "string_value" : "2010-09-09 19:52:45+0000"
         },
         "process_exit_time" : {
            "type_name" : "UnixTimeStamp",
            "value" : 0,
            "string_value" : "-"
         },
         "handle_count" : 325,
         "ppid" : 1084
      }
   ]

R=amoser@google.com

Review URL: https://codereview.appspot.com/114120043