Minor popups comment tweak (#402)

imgui.cpp

@@ -3075,6 +3075,8 @@ static bool IsPopupOpen(ImGuiID id)
     return opened;
 }
 
+// Mark popup as open. Popups are closed when user click outside, or activate a pressable item, or CloseCurrentPopup() is called within a BeginPopup()/EndPopup() block.
+// Popup identifiers are relative to the current ID-stack (so OpenPopup and BeginPopup needs to be at the same level).
 // One open popup per level of the popup hierarchy (NB: when assigning we reset the Window member of ImGuiPopupRef to NULL)
 void ImGui::OpenPopup(const char* str_id)
 {

imgui.h

@@ -345,7 +345,7 @@ namespace ImGui
     IMGUI_API bool          MenuItem(const char* label, const char* shortcut, bool* p_selected, bool enabled = true);              // return true when activated + toggle (*p_selected) if p_selected != NULL
 
     // Popup
-    IMGUI_API void          OpenPopup(const char* str_id);                                      // mark popup as open. popup identifiers are relative to the current ID-stack (so OpenPopup and BeginPopup needs to be at the same level). close childs popups if any. will close popup when user click outside, or activate a pressable item, or CloseCurrentPopup() is called within a BeginPopup()/EndPopup() block.
+    IMGUI_API void          OpenPopup(const char* str_id);                                      // mark popup as open. popups are closed when user click outside, or activate a pressable item, or CloseCurrentPopup() is called within a BeginPopup()/EndPopup() block. popup identifiers are relative to the current ID-stack (so OpenPopup and BeginPopup needs to be at the same level). 
     IMGUI_API bool          BeginPopup(const char* str_id);                                     // return true if popup if opened and start outputting to it. only call EndPopup() if BeginPopup() returned true!
     IMGUI_API bool          BeginPopupModal(const char* name, bool* p_opened = NULL, ImGuiWindowFlags extra_flags = 0);             // modal dialog (can't close them by clicking outside)
     IMGUI_API bool          BeginPopupContextItem(const char* str_id, int mouse_button = 1);                                        // helper to open and begin popup when clicked on last item