As of 1.6.7, this addon is unnecessary

Unifies Crit-Shrug-Off into one predictable stat.

Currently, several talents say "all direct critical hits (physical, mental, spells) against you have a X% lower critical multiplier (but always do at least normal damage)". This was a lie. What these talents actually do is give you a X% chance to remove extra critical damage.

In this addon, Crit Shrug Off reduces the critical multiplier on incoming damage.
With 20% Crit Shrug-Off, a basic critical hit will go from 150% to 130%.
With 50% Crit Shrug-Off, a basic critical hit will go from 150% to 100%, no stronger than a normal hit.

Since everyone has some Crit Shrug Off from dexterity, this makes critical hits weaker, but more reliable.

Furthermore, there were 2 related statistics, Crit Reduction and Crit Shrug Off. This addon replaces all sources of Crit Reduction with Crit Shrug off.
Crit Reduction was present on Heavy Armour Training, Alchemist Golems, Borfast's Cage, and Daneth's Neckguard.

Technical Details
This replaces the Default damage projector, because the hook DamageProjector:base is not actually at the base of the projector, but rather comes right after the critical calculation.
CalculateCritReduction is superloaded to ignore the combat_crit_reduction stat, and the armor talents have been superloaded to grant ignore_direct_crits instead.