Added modal dialog example (#249)
Added modal dialog example (#249)

dougbinks/imgui,nmlgc/imgui,cmaughan/imgui,benoitjacquier/imgui,Flix01/imgui,emoon/imgui,Pagghiu/imgui,ocornut/imgui,redblobgames/imgui,neshume/imgui,aimotive/imgui-glfw,ocornut/imgui,bkaradzic/imgui,bkaradzic/imgui,bkaradzic/imgui,xythobuz/imgui,zho7611/imgui,redblobgames/imgui,wasikuss/imgui,tom-seddon/imgui,wflohry/imgui-addons,nmlgc/imgui,ggtucker/imgui,benoitjacquier/imgui,thennequin/imgui,thevaber/imgui,Psybrus/imgui,Flix01/imgui,wangshijin/imgui,rmoorman/imgui,luiseduardohdbackup/imgui,wangshijin/imgui,seanmiddleditch/imgui,ghassanpl/imgui,sakishum/imgui,mikesart/imgui,bagobor/imgui,shaggytwodope/imgui,twigletguy/imgui,emoon/imgui,aimotive/imgui-glfw,Pagghiu/imgui,gyakoo/imgui,thevaber/imgui,luiseduardohdbackup/imgui,usagi/imguixx,zho7611/imgui,twigletguy/imgui,burningreggae/imgui,cmaughan/imgui,neshume/imgui,xythobuz/imgui,tom-seddon/imgui,GHF/imgui,cmaughan/imgui,wasikuss/imgui,mikesart/imgui,xunmengfeng/imgui,tpoechtrager/imgui,bagobor/imgui,thennequin/imgui,ghassanpl/imgui,kylawl/imgui,andresv/imgui,ggtucker/imgui,shaggytwodope/imgui,usagi/imguixx,nProtect/imgui,Psybrus/imgui,tpoechtrager/imgui,ggtucker/imgui,xunmengfeng/imgui,Flix01/imgui,GHF/imgui,elect86/imgui,burningreggae/imgui,dougbinks/imgui,cmaughan/imgui,ocornut/imgui,seanmiddleditch/imgui,gyakoo/imgui,nProtect/imgui,nProtect/imgui,elect86/imgui,andresv/imgui,rmoorman/imgui,kylawl/imgui,sakishum/imgui,wflohry/imgui-addons,rxantos/imgui,rxantos/imgui