CDData checking on file load was not taking into account deprecated CD_MTEXPOLY datatype, which unfortunately shows same weird glitch as CD_PAINT_MASK and CD_FACEMAP ones... Note that it was annoying (due to amount of warnings in console), but totally harmless, since that data type is just deleted anyway. This commit also generally cleans up the CD_MTEXPOLY deprecation code, we have a system to handle that, let's use it, instead of defining local static values to replace it...