Added hair colours brown, dark-blonde, gray, light-blonde, and white.
dark-blonde was from the LPC base assets, the others from Luke Mehl's
submission. (But maybe he took them from the base assets as well -- I could
not open the xcf in the base assets, only the png.)

So far only the female bangslong hairstyle is covered. More are planned.

Excepting the white hair, the new colours have one colour more than the
hair colours which already were in the universal sprite sheet. The extra
colour is a highlight on shiny parts. The white hair is so bright that no
highlights show up. So further hair recolours might want to take, e. g.
hair/female/bangslong/dark-blonde.png as a basis instead of
hair/female/bangslong.png.