ImFontAtlas: Tweak to allow MergeMode to apply on a font that isn't the previous one, by setting the DstFont field.
ImFontAtlas: Tweak to allow MergeMode to apply on a font that isn't the previous one, by setting the DstFont field.

mikesart/imgui,dougbinks/imgui,cmaughan/imgui,Psybrus/imgui,emoon/imgui,burningreggae/imgui,Flix01/imgui,wasikuss/imgui,nProtect/imgui,ocornut/imgui,usagi/imguixx,ggtucker/imgui,elect86/imgui,thennequin/imgui,dougbinks/imgui,usagi/imguixx,ggtucker/imgui,seanmiddleditch/imgui,Pagghiu/imgui,aimotive/imgui-glfw,wflohry/imgui-addons,Psybrus/imgui,ocornut/imgui,seanmiddleditch/imgui,Pagghiu/imgui,bkaradzic/imgui,rxantos/imgui,thennequin/imgui,bkaradzic/imgui,wasikuss/imgui,burningreggae/imgui,tom-seddon/imgui,cmaughan/imgui,ggtucker/imgui,thevaber/imgui,nProtect/imgui,Flix01/imgui,mikesart/imgui,cmaughan/imgui,emoon/imgui,elect86/imgui,rxantos/imgui,wflohry/imgui-addons,aimotive/imgui-glfw,cmaughan/imgui,thevaber/imgui,Flix01/imgui,bkaradzic/imgui,ocornut/imgui,tom-seddon/imgui,nProtect/imgui