Velothi Temple and Siltstrider Port Improvements

[BethOfDeath]

ex_velothi_temple_02:

• Simplified, split, combined, and scaled collision mesh to reduce calculation volume and somewhat correct minor inaccuracy relative to visual mesh.
• Added LOD reducing from 5 drawcalls to 1
• Previously: 47407 bytes; new: 67788. (+43%)

ex_velothi_temple_01:

• Added two LODs, reducing from 7 drawcalls to 4, then to 3, and simplifying geometry.
• Previously: 70453 bytes; new: 126832. (+80%)

ex_velothi_striderport_01:

• Collision mesh did not cover entirety of visual mesh, limiting the height at which it could be used even beyond what the relative height of a siltstrider dictates. Adjusted collision posts and chopped into sufficient pieces to minimize computation volume. -- Also split platforms' collision meshes, as they tended to reach to the ground or nearly so. -- New collision meshes total 266 tris in 33 pieces instead of the former 94 in 9, but I'm hoping to find less of an FPS impact moving around underneath and atop it.
• Added, or replaced, edgeloops on platforms and walkway, to improve vertex lighting.
• Removed sharp edges from tx_wood_docks mesh as they were not helpful at causing better normals and may have been an artifact of importing anyway. Added some to the actually-flat platform, where they _do_help
• Reweighted normals.
• Retopologized triangle-fan endgrain to max-area, saving 32 tris and possibly a little overdraw... somewhere.
• Added LODs, reducing from 6 drawcalls to 4, then 2.
• Previously 111238 bytes; new: 201005. (+81%)