Patch 5 : Multiple function optimizations

**New:**​ Items sold to shops can now be repurchased at their original price from that same shop (they will be retained for 2 turns).

**New:**​ Auto-save slot upon ending a turn.

**Adjustment:**​ Skill Transmission now supports both the new (consuming Skill Points after a skill is maxed out) and the old (using a skill book on someone who already knows that skill) modes.

**Adjustment:**​ Reduced the Skill Points cost for Skill Transmission.

**Adjustment:**​ Holding the Z key for fast-forward will no longer skip across cutscenes.

**Fix:**​ Issue where it was still possible to pledge allegiance to the ShengJianMen Sect after its destruction.

**Fix:**​ Issue where Night Crow would still attack the ShengJianMen Sect after its destruction.(Would result in JiYeman's erroneous death.)