change make2columnfits to makefits in z2nparallel
add addlc.py: add 2 lightcurves (to be used to crate EPIC combined lightcurves)
add comparelcs.py: calculates ratio, hardness and sum of 2 lightcurves
add plotcolumns.py: plot columns (like xmm's dsplot)
add scattercolumns.py: same as plotcolumns, but scatter
add scatterfiles.py: same as scattercolumns, but for multiple files
add lcperiod.py: runs the lomb-scargle periodogram in a lightcurve (CHECK BUG in freqs)