WW Model Helpers 1.3.1

• The preview generator script now supports custom pupil colors with or without color masks, and color masks for mouth colors.
• pack_player now autodetects the name of the .arc by looking in the clean model folder for the only file name that ends in .arc, so you don't have to manually use the -rarcname argument. (However, if the folder has multiple .arc files in it, you must specify -rarcname or it won't know which to use.)
• Fix "All vertices unweighted" error not properly letting you know what model has the error.
• Fixed a bug when encoding standalone .bti files with the CMPR format where large areas of transparency would be encoded as black instead of transparent.