Switch from object to array of instances
Add class to all images init’d with plugin

Easier control with CSS.
Refactor images matching

* Remove getVisibleImages method, it’s functionality is now more easier
to control
* Add images set reduction for lazyloaded images
* Simplify methods for parsing lazyloaded and postponed images
Update test
Remove Picture parser support

Move to feature branch for later addition.
Update README
Release 0.1.1