UE1: Add support for Deus Ex format vertex data.
UE1: Group triangles by skin index AND type/flags (preparation for per-surface render style support).
UE1: Add handling of Weapon Triangle (preparation for model attachment support).
UE1: Support flat shaded triangle flag.
(concatenated "UMSH" signature + datafile + anivfile)
This is pretty much 100% functional by now.
Hasn't been tested on platforms other than Linux yet, though.
Code definitely deserves some cleaning.