Now saves in the desired format

The data is now saved in the follwing format with each spectra grouped together:

{spectrum number}

[optional]{comment marker}X,Y,E[optional],DX

X(0,0){separator}Y(0,0){separator}Z(0,0)[optional]{separator}DX(0,0)

X(0,1){separator}Y(0,1){separator}Z(0,1)[optional]{separator}DX(0,1)
...

{spectrum number}
...

Refs #7732