Incompatible shapes error could give more information.

[gilescope]

Incompatible shapes error could give more information about the dimentions that do and don't match.
It would be great to see if it's an off by one error or whether it's a fundermental shape missmatch.

Would be great to see (10,20,1) != expected shape (20,10,1) as an error message.

I'm guessing shape mismatches will happen quite frequently for users as they are developing so excellent errors will speed up the dev process.

Thoughts?