Update passport.js to handle errors 

Updated  strategies to handle error when user tries to authenticate with a strategy after he has used his email to authenticate using other strategies.
Included comments on product listing & detail page

plannifnminus1fails/destiny#6
Comments package gets update

plannifnminus1fails/destiny#6
Removed article example pages link from menu

plannifnminus1fails/destiny#6
Update README.md
Update README.md
Add description to product

Replaced all instances of `content` to `description` in `products` package

plannifnminus1fails/destiny#6
Added tag to product

plannifnminus1fails/destiny#6
Merge pull request #806 from exoer/patch-2

Update passport.js to handle errors
Angular controller & views updated for tag attribute in products package

plannifnminus1fails/destiny#6
Color and category added to product

plannifnminus1fails/destiny#6
Test updated in products package for latest changes

plannifnminus1fails/destiny#6
force build
Alignment fixed at product add & edit form

plannifnminus1fails/destiny#6
Now guest Users can view products

plannifnminus1fails/destiny#6
Adding mean.json and mean-admin core dependency
User gets product listing page on successful delete a product

plannifnminus1fails/destiny#6
Product details page Alignment issue is fixed

plannifnminus1fails/destiny#6
Intermediate code
Included @veljkopopovic change to fix gmap, changed mongoose debug to false, changed debug to true for non-uglified code on development