Add plot_stresses() function.

[u-anurag]

A function to show stress distribution in 2D and 3D shell, Tri, and brick elements.

[cslotboom]

So am I correct that you have been working on both plot stress and plot strain?
It might be worth looking at the zhuminjie#43 - I noted there are some stress functions there.

[u-anurag]

I am working on both. I have seen it and that will not work for 3D elements.

[cslotboom]

Okay, good to know! If you want any feedback, feel free to pop them into the experimental functions.