Update on search module


**Functionalities implemented:**

NOTE: Please run following command - ```python manage.py search_scripts -c```

1) Updated: management/commands/search_scripts.py
 
   - Reverted to code of commit #e982ab8c2bba0738dd5b7a331dac859be30f3fd5
   
   - Added if-else checks for url set-up
   
     - The problem was: urls aren't getting set for few of the forum & it's thread/twist documents as well as for file documents
     
   - Commented unecessary for loop at the end.
   
2) templates/ndf/search_page.html
 
   - For few of the GSystems, url is set as None. Because of this, when such documents are found in search and passed for rendering on templates they were causing problems in javascript (as value found for them was null).
   
   - So to tackle this, if-check is put which checks if value is not null then only process documents!
   
3) views/search_views.py
 
   - Rewinding a cursor was missed, which is updated now!
     
4) Deleted: gnowsys_ndf/ndf/adv_search_results.html

   - Misplaced html template removed.