Weapon and shield updates

I update fairly regularly. Most, however, are to fix typos or provide rule clarifications. The most recent round went a bit farther. Some weapons, particularly those with the precise and percussive tags, didn't offer the intended advantages against heavier armour types when compared to other weapons in their class. And, shields were a bit too protective, particularly when wielded by PCs with high levels of Reflex. This update addresses those concerns. But, please let me know if there are continued problems or inconsistencies.