do not load adaptive img if wrapper has the .lazy class, and still display the preview img in this case, until the .lazy class is removed
No cid class on <img> tag : redondant as already on wrapper and targeted by mistake by CSS selectors
Additional lazyload property : if true loading of adaptive images will be delayed by a .lazy class on <html> tag.
The user has to insert additional JS in order to move .lazy on .adapt-img-wrapper, remove it from <html> and then from visible wrappers when necessary
v1.7.0 that allow to delay load of adaptive images