Added missing info about building Fuel ISO on 64 bit system only
Added missing info about building Fuel ISO on 64 bit system only

Change-Id: Idefb05894382ab773e4d27836984e0da3bcf48a4
Closes-Bug: #1393571

eayunstack/fuel-web,zhaochao/fuel-web,eayunstack/fuel-web,stackforge/fuel-web,prmtl/fuel-web,prmtl/fuel-web,zhaochao/fuel-web,zhaochao/fuel-web,SmartInfrastructures/fuel-web-dev,nebril/fuel-web,stackforge/fuel-web,nebril/fuel-web,SmartInfrastructures/fuel-web-dev,huntxu/fuel-web,SmartInfrastructures/fuel-web-dev,zhaochao/fuel-web,prmtl/fuel-web,nebril/fuel-web,huntxu/fuel-web,SmartInfrastructures/fuel-web-dev,prmtl/fuel-web,huntxu/fuel-web,eayunstack/fuel-web,nebril/fuel-web,eayunstack/fuel-web,huntxu/fuel-web,huntxu/fuel-web,prmtl/fuel-web,SmartInfrastructures/fuel-web-dev,zhaochao/fuel-web,eayunstack/fuel-web,nebril/fuel-web,stackforge/fuel-web