fix broken (not smooth) pixel when crop image

[ThanhLD24]

I add some code to resolve the broken or not smooth image problem when image is cropped.
You can see the change I have presented in example below:
https://jsfiddle.net/thanhld24/n7ja32qb/
Ps: please read the note what I commented in javascript frame in jsfiddle

[theodorejb]

The canvas imageSmoothingEnabled property already defaults to true, and in my testing changing the imageSmoothingQuality value does not fix the issue. I ended up forking Croppie and implementing a different scaling algorithm for higher quality results: https://github.com/theodorejb/cropt