add NaN checks for input matrix A in GEEV, return error if NaN are in matrix A, NaNs in input are detected with LANGE (needed for scaling)

[langou]

This adds a NaN check on the entries of the input matrix A in GEEV,

GEEV would now return error INFO = -4 if there are NaNs in matrix A in input.

NaNs in input are detected with LANGE. Since LANGE is called for scaling anyway, there is no extra cost.

This follows @angsch's suggestion in issue #1128. This uses DISNAN instead of DISFINITE (as initially suggested). I am not opposed to create a DISFINITE function and use it, but I think it needs more decisions and consensus.

See as well PR#471 for a "similar" behavior.