Removed unnecessary ImGui:: prefixes.
Removed unnecessary ImGui:: prefixes.

cmaughan/imgui,ocornut/imgui,ggtucker/imgui,aimotive/imgui-glfw,burningreggae/imgui,dougbinks/imgui,cmaughan/imgui,ocornut/imgui,dougbinks/imgui,ggtucker/imgui,Flix01/imgui,burningreggae/imgui,bkaradzic/imgui,bkaradzic/imgui,nProtect/imgui,aimotive/imgui-glfw,bkaradzic/imgui,Flix01/imgui,ocornut/imgui,ggtucker/imgui,nProtect/imgui,nProtect/imgui,Flix01/imgui,cmaughan/imgui,cmaughan/imgui