profile: make image upload more userfriendly

[gerolsteinernaturell]

1. Please add a transparent layer with an upload icon on the image, so that users know how to upload/change their profile image.
2. After uploading, you should see a round section in which you can move the image to display only this section.

[gerolsteinernaturell]

• number 2 still missing (Selection)
• sometimes the images are distorted (aspect ratio should never be changed)