Improve two-point clustering of synthetic dwarf galaxies

[aphearin]

As discussed with @chihway today, the current treatment of synthetic dwarf galaxies could be improved by giving the field dwarfs a tunable level of large-scale bias, as in de la Torre & Peacock 2013, and also by making a fraction of the dwarfs satellites. Having tunable levels of these effects would make the mocks more useful for studies of dwarf galaxy lensing.

[aphearin]

Steven Murray's powerbox code might also be useful for this or related purposes, though a naive application of it would not correlate with the DM field and so would not result in realistic lensing.