Enhancement suggestion: more scripts for NIF work routine

[isshininu]

Hello matortheeternal thank you for developing useful NIF scripts for TES5Edit (I am using version 4.0.3), script for updating tangents works like a charm! I've come with idea for more automation scripts and with notable examples:

1. the first is "Remove duplicate vertices"
2. and the second is much more complex, aimed to be a workaround for current existing 3DS MAX NifTools plugins that destroy shader flags on export (notable example is shader flag 2 "EnvMap_Light_Fade" that being eliminated on exporting meshes with Skyrim Shader Type "Default"). Being able to use tool that could mass change shader flags might be useful.