Details:
- Added logic to level-1v, -1d, -1f, -1m, -2, and -3 operations' _check()
functions to ensure that all operands are of the same datatype. There
are some exceptions that were left out, such as the _check() function
for the various norm operations since they have a different idea of
datatype consistency (ie: the norm object must be the real projection
of the primary input vector/matrix object).