Fixes a typo that prevented Album's getReleaseDate() from working.
Fix getImage() failing on 'small' images.
Add access to User's real name and registration date.
Avoid warning when accessing unixtime attribute.
Messed a comment a bit: tabs vs spaces.
Fixed warning when a image size is missing.
Actually allow the function return null for missing image sizes.
Merge https://github.com/m4tthumphrey/php-last.fm-api