Performs a matrix-vector multiplication between mat (2D tensor) and vec (1D tensor), multiply by the scalar value and add it to self. In other words, 

self = self + value * mat*vec

Sizes must respect the matrix-multiplication operation: if mat is a n x m matrix, vec must be vector of size m and self must be a vector of size n. 

> x = torch.Tensor(3):fill(0)
> M = torch.Tensor(3,2):fill(3)
> y = torch.Tensor(2):fill(2)
> x:addT2dotT1(1, M, y)
> = x

 12
 12
 12
[torch.Tensor of dimension 3]