Updated version.txt for VIET 1.6.1

I saw a mudcrab the other day, horrible creatures.
Merge pull request #14 from cybrxkhan/beta

VIET 1.6.1
Merge pull request #15 from thefinestsieve/beta

Added Sogdian icons
Deleted VIET Immersion Files Overlapping with CPR

RIP Portrait Fix
More VIET Immersion-CPR split tweaks
AO 2.0 Ambition Tweaks
Merge pull request #16 from cybrxkhan/beta

Last stuff for RC 2.0
Reduced prestige cost of pagan subjugation
Merge pull request #17 from cybrxkhan/master

Switcheroo