Add round profile to crop.

[hearsilent]

No description provided.

[loeschg]

Would love to have an oval cropping style!

[Rainer-Lang]

+1

[shliama]

Yes, round & oval cropping style option will be added soon.

But I cannot accept this pull request, because:

1. It has huge performance issues. You call drawRoundProfile() method for each frame drawn which in turn does tremendous amount of work (e.g. allocating memory for new objects). Please check out this video: https://www.youtube.com/watch?v=HAK5acHQ53E
2. Furthermore the result of what you try to accomplish doesn't look correct too.

Stay tuned for updates 📻

[hearsilent]

@shliama

Thanks for your suggestion.

1. I had commit code to fix it.
2. This pull request only show round profile preview for what apps wants show both round photo & rectangle photo, that can improve user who want to know if his photo round crop.

hearsilent@032e14a

If you think this commit is ok, I will open pull request again.