* consolidate code for drawing backsides
* drawSetNames: no need to calculate xPos / yPos per card
* Account for back_offset when calculating set name placement
Without this, if you had a negative back_offset_height (or
positive back_offset), it was possible to print set names that
would intrude onto the divider area on the backs
* draw setNames along side (left or bottom) with more space
This both provides more cushion, and makes it less likely that
location will change between front + back (due to back_offset_height)
