Added MIFU007 to MANGAmap, re-implemented PD correction to MANGA_bench

I don't know why the PD correction had be turned off before. In any case,
it should be on and it's only about 1% anyway.
Added flares to Salty2, changed interaction with simcurve

New function is Salty2.disco(). Salty2.simcurve() now has two new keyword
args, spiralpars and flarepars. These are expected to be dictionaries that
contain the parameters relevant to spirality and flares, respectively. If
they are not given then no spirals or flares are added to the galaxy.

starting