Add a score for each user

[shivakrishna9]

Based on views of links posted by a user, a score is assigned to the user such that top link-contributer has better score.
The score better be called as 'karma' as he is posting it solely for others benefit.

This encourages people to post more links to linklet more often. It is a nice to have feature but not a must have one.

[vinaypuppal]

Will be implemented soon in next upgrade.