removed frame numbering from BLI_convertstringcode into its own function (BLI_convertstringframe), many uses of BLI_convertstringcode were passing dummy frames values anyway. in cases where adding the current frame number to a filename is needed run BLI_convertstringframe(...) after BLI_convertstringcode(...) There are some cases Im not sure BLI_convertstringframe is needed, these have been commented as todo, but at least have the same functionality they used to.