Update Windows dev README
Update Windows dev README

1. For currently used MSVS2012
2. For the switch to git

Sp1l/pwsafe,Sp1l/pwsafe,Sp1l/pwsafe,Sp1l/pwsafe,Sp1l/pwsafe,Sp1l/pwsafe,Sp1l/pwsafe,Sp1l/pwsafe