Implements TRPAISV inside a CUDA block (test inc)

* TRPAISV stands for "TRiangular matrix Plus Alpha times Identity Solve
  for Vector". It is similar to TRSV, put an alpha value is given and
  added (subtracted in this case) from each element in the matrix main
  diagonal. This function eliminates the need for temporary storage
  space in the BartelStewart algorithm.
* Also, this commit fixes TRSV.