Merge branch 'master' into jgrpp

# Conflicts:
#	src/company_gui.cpp
#	src/group_gui.cpp
#	src/newgrf.cpp
#	src/newgrf_debug_gui.cpp
#	src/saveload/saveload.cpp

src/fios.h

@@ -59,7 +59,8 @@ void FiosGetHeightmapList(SaveLoadOperation fop, FileList &file_list);
 
 bool FiosBrowseTo(const FiosItem *item);
 
-StringID FiosGetDescText(const char **path, uint64 *total_free);
+std::string FiosGetCurrentPath();
+std::optional<uint64_t> FiosGetDiskFreeSpace(const std::string &path);
 bool FiosDelete(const char *name);
 std::string FiosMakeHeightmapName(const char *name);
 std::string FiosMakeSavegameName(const char *name);