Update easyzoom.js

Fixed the issue with image not showing up when mouse enters from bottom on images with odd sizes.
Merge pull request #42 from zarneckin/master

Fix adjacent image not showing
Add srcset functionality
Use jQuery.isArray instead of if not condition
Merge pull request #48 from i-like-robots/pr/45

Add support for srcset
Fix issue with relative mouse position being negative, closes #44
Bump version no, release 2.2.1!
Merge pull request #43 from i-like-robots/release/2.1.1

Release/2.2.1