anchor.diff:  
   
   --
  -Search Suggestions
  +Suggestions
   --
   Get suggestions for user query.
   
  
positive.code: 
  #### view
  
  tbd
  
  #### model
  
  tbd
  
  GET /rest/suggestions/query_string?q={user_query_string}
  < 200
  
negative.code:         "suggestions": {
              "caption": "Query Completions",
              "options": [
                  "option #1",
                  "option #2",
                  "..."
              ]
          },
          "filters": {
              "caption": "Filters",
              "options": [
                  "option #1",
                  "option #2",
                  "..."
              ]
          },
          "mails": {
              "caption": "Mails",
              "options": [
                  "option #1",
                  "option #2",
                  "..."
              ]
          }
      },
      "model" : {
          "search": { 
              "search": { "query": "${query_string}" }
          },
          "suggestions" : [
              { "action #1" },
              { "action #2" },
              { "..." }
          ],
          "filters": [
              { "action #1" },
              { "action #2" },
              { "..." }
          ],
          "mails": [
              { "action #1" },
              { "action #2" },
              { "..." }
          ]
      }
  }
  