update build doc to point out need lua now
update build doc to point out need lua now

hughperkins/DeepCL,pimms/DeepCL,pimms/DeepCL,MiniLight/DeepCL,FighterLYL/DeepCL,Peilong/DeepCL,pimms/DeepCL,mrgloom/DeepCL,MiniLight/DeepCL,MiniLight/DeepCL,FighterLYL/DeepCL,Peilong/DeepCL,FighterLYL/DeepCL,mrgloom/DeepCL,hughperkins/DeepCL,mrgloom/DeepCL,hughperkins/DeepCL,MiniLight/DeepCL,Peilong/DeepCL,pimms/DeepCL,mrgloom/DeepCL,FighterLYL/DeepCL,hughperkins/DeepCL,mrgloom/DeepCL,pimms/DeepCL,MiniLight/DeepCL,hughperkins/DeepCL,FighterLYL/DeepCL,Peilong/DeepCL,Peilong/DeepCL