reshape and _new_like_me should respect matrix ordering

[andrewcron]

I modified GPUArray.reshape to respect the matrix ordering and allow changes to the ordering as in numpy. I also changed _new_like_me to keep the old ordering.

In general, I think elementwise functions should respect the matrix's ordering. I'm not sure if changing _new_like_me will cover all of the cases. I'm somewhat new to collaborative python programming so please let me know what you think.

Thanks!