refresh VFS on model refresh, refresh models on VFS refresh

refresh VFS on model refresh, refresh models on VFS refresh

Before:

- refreshing textures were refreshing VFS (to load enabled texture packs)
  but models were not refreshed
- refreshing textures were refreshing models but textures would be missing
  since the VFS was not refreshed and texture packs would be not loaded

After:

- refreshing textures or models both refresh VFS, textures and models,
  this way you don't anymore reload models without refreshing textures, or
  refresh VFS without reloading models, etc.