Draw fSlaveFeed art post-inflation and fix vagina checks for lube increase

As per my inquiry in !11291 (merged). Tested and working properly.

Also tossed in a few unrelated issues I noticed afterward. Most significantly, standardized all vaginaLube increases to check vagina >= 0 vagina !== -1 rather than vagina > -1, and fixed a few that checked vagina > 0 (and thus wouldn't fire for virgins) or didn't check vagina at all and could thus trigger with only an anal womb.