shape integer overflow

[Bihaqo]

lazy_shape overflows for large tensors and matrices ValueError: Dimension -2101438300051996672 must be >= 0

[Bihaqo]

Same problem in gram_matrix (need to finally make "is_matmul_applicable" or something like that!):

vectors_shape = tt_vectors.get_shape()
if vectors_shape[2] == 1 and vectors_shape[1] != 1:

and in str method.