Fixed cropRect size being incorrectly calculated some aspect ratios.
The cropRect is now centered when PECropView.setCropAspectRatio is used to define a crop rect.
Update README.md
Update README.md
Merge pull request #19 from rivera-ernesto/pawelkw_enhancements

Pawelkw's enhancements
Update podspec.
Refine drawing grid.
Clean up.
Clean up.
Clean up.
Update podspec.
Update README.md
Merge pull request #1 from kishikawakatsumi/master

sync from main repo