STR - VIT Difference Function

fSTR
fSTR is the damage bonus from your STR - monster VIT for melee attack.
 * fSTR is calculated by fSTR2/2. So, melee attack needs roughly 4~6 STR to increase fSTR value by 1
 * When STR-VIT value is high, fSTR can be approximated by (your STR - monster VIT+4)/4
 * fSTR value is somehow affected by weapon rank
 * The upper cap of fSTR is ( weapon rank+8)

fSTR2
fSTR2 is the damage bonus from your STR - monster VIT for ranged attack
 * It takes roughly 2~3 more STR to increase fSTR2 by 1 depending on how big is your STR - mob VIT value
 * When STR-VIT value is high, fSTR2 can be approximated by (your STR - monster VIT+4)/2 and
 * fSTR2 value is somehow affected by weapon rank
 * The upper cap of fSTR2 is ( weapon rank+8) x 2