fix bug 1030629 - search filter

Hi,
It seems to be working right now :)

- The waffle flag "search_suggestions" is needed to make all work, if not present the script is not loaded.
- The welcome message is only shown when item "supressSearchSuggestions" is not set in localstorage. Clear localstorage in the page ( "localStorage.clear()" in the FF console ) and reload the page to show the message again. 
- I've added some changes to the original "search-suggestions.js" file to make it work with the right column in the results page.
- I've only tested with 3 test entries that I've added by hand into my kuma installation.
- I've added the changes in the phyton files without knowing very well what I was doing... I've only copy/paste the new lines, but maybe someone can take a look and see if I've done something stupid.

Let me know what do you think.