Now profile image can be set using RT has_profile_pic with its user

Profile image can be uploaded in user dashboard. It has been set according to RT defined as 'has_profile_ pic' . Previously it was set according to GST "profile_ pic" by defining image "type_of" for differentiating profile image with other images stored in DB. 
Now just by creating an RT "has_profile_ pic" , relation has been created for author with its profile image.

Modification in :
```
filldb.py  -->  GST 'profile_pic' is removed, and RT 'has_profile_pic' is created 
user.py  -->  urls modified for userDashbaord, unecessary arguments are removed  
userDashboard.py  -->  Implemented logic for creating relation of user with its uploaded profile image
userDashboard.html  --> Little modification in template for url redirection in userDashboard view
base.html  -->  unecessary arguments are removed from userDashboard urls defined in this template
ndf_tags.py  --> 'get_profile_pic' method modified 
file.py --> "type_of" statement is removed while storing an profile image 
```
[NOTE: Please do "python manage.py filldb" after making latest pull ]