[Sub-Mod] AGOT Obligation Law Opinions

I didn't like how opinion modifiers disappeared once there was a change in rule from the one who changed an obligation law, so I created this little sub-mod. What this does is add permanent opinion modifiers which are tied to the levels of the obligation laws. For example, feudal vassals, as in described in the game description, prefer more taxes as opposed to providing more levies. Changing the obligation law, in this case, towards more taxes will net a positive opinion modifier (gets higher the further you go) while going the opposite direction will provide a negative opinion modifier. City vassals prefer providing more troops rather than paying more taxes and temple vassals will prefer a balance of the two.