Use clipping masks for layers

It will be cool to give the possibility to clip layers to an other (like in Photoshop) to only display the part of selected layers (make option : "Clipped : No / Yes") which are intersected with the first bottom layer which have not the clipped option.

Example :

- Layer 0 : Background with "Clipped : No"
- Layer 1 : Oval shape with "Clipped : No"
- Layer 2 : Minutes Hand with "Clipped : Yes"
- Layer 3 : Hours Hand with "Clipped : Yes"
- Layer 4 : Date Text with "Clipped : No"
- Layer 5 : Square shape with "Clipped : No"
- Layer 6 : Logo with "Clipped : Yes"
- etc...

The clock hands will be displayed only in the oval shape (parts of the hands which are out of this oval will be hide).

And the logo will be displayed only in the square shape (parts of the logo which are out of this square will be hide).