updated readme to reflect compatibility with WP v3.9.2
better control over bailing out filter
attach hooks and make filters available at a later point so as to provide proper opportunity to plug in
init plugin only when we are on a compatible WP version
proper way of retrieving queried object ID outside the loop, and bumping up the minimum WP version requirement
bug fix:  array has IDs as key, so get the first element properly + use full size image instead of thumbnail
tagging as v0.3.3