Change header of the current

Following the mailing remark

If I use octopus for a triclinic crystal, what kinds of basis (unit
vectors) are the time-dependent observables, e.g. the current using?


In the case of the current the output file reads "Iter  t  I(1) I(2)
I(3)   In1)   In2)  In3)   I-sp1(1)  I-sp1(2) I-sp1(3)".

Are 1,2,3 the cartesian axes xyz, the unit vectors of the crystal abc or
a normalized abc? 

we should change 1,2, and 2, to x, y, and z.