Fixed Shiv.

* Now it does weapon dmg and adds a combo point even without poison (yes, that's blizzlike).
* Poisons from Shiv cannot crit.
* No more double poison procs.

--HG--
branch : trunk

src/server/game/Entities/Unit/Unit.cpp

@@ -10445,7 +10445,7 @@ bool Unit::isSpellCrit(Unit *pVictim, SpellEntry const *spellProto, SpellSchoolM
                     }
                 }
                 // Custom crit by class
-                switch(spellProto->SpellFamilyName)
+                switch (spellProto->SpellFamilyName)
                 {
                     case SPELLFAMILY_DRUID:
                         // Starfire
@@ -10458,6 +10458,11 @@ bool Unit::isSpellCrit(Unit *pVictim, SpellEntry const *spellProto, SpellSchoolM
                            break;
                         }
                     break;
+                    case SPELLFAMILY_ROGUE:
+                        // Shiv-applied poisons can't crit
+                        if (FindCurrentSpellBySpellId(5938))
+                            crit_chance = 0.0f;
+                        break;
                     case SPELLFAMILY_PALADIN:
                         // Flash of light
                         if (spellProto->SpellFamilyFlags[0] & 0x40000000)