Merge pull request #75 from camilotorresf/fixes

Migration of pin images to S3
S3 images names only lowercase and + numbers
Use a bit less numbers in S3 file name generation
Fix edit pin in profile
Fix displacement headers

When loading, for 1 sec the page shows all skewed and
bad formatted. Now shows normal
Fetch more items in listings
Put the more sensitivity to scroll control
Lazy load images in category listing
Lazy load images in lists