Fixes memory leak when loading PNG images

0.4.4

Fixes regression test

Fixes crop offsets

0.4.3

Fixes bounds on cropping

Added new relative transforms for width/crop offsets

0.4.2

Updates crop transform and scalar API

Pipeline -> Transform

Merge pull request #9 from davidbyttow/d/transform

Implements new transform API

New API

This release includes several important things:

• Rewrites the entire Image API
• Adds a Pipeline API
• Fixes memory leaks