prDiet minor tweaks

Noticed that breast redistributors dropped one of my slaves to a boobs value of 35. Have gone through the code and added limits to risky sources of breast shrinkage, to avoid breast size falling below the current flat value of 100. Have two major concerns before I un-draft:

1. Did I go too far adding the drug cessation conditions to PC breast redistributors?

2. More importantly, should this be setting Math.max(x.boobs, 100 + x.boobsImplant + x.boobsMilk) instead of Math.max(x.boobs, 100) as I currently have it? I'm pretty sure I'll need to anywhere that defines boobSize, but not sure if it's warranted elsewhere.

UPDATE: This MR now just tweaks some boobSize comparisons and spaces out a subtraction operation.