Splits original mesh into regular and irregular meshes and renders them
separately.

findRegular returns two index buffers, one for regular triangles and one
for irregular ones.

helper method for finding and matching triangles. fixed some codependent indices in patch index buffer computation.

This reverts commit 6ee50809.

Added 12 Patch start

(when a triangle can't find all three adjacent vertices: don't create new edge points, keep indices for old triangle. Still creates holes though, since vertex points are moved anyway.)

started patch detection. compiles, not used yet. stopped because I don't know what a patch is supposed to do.

normal fix

some changes to Mesh entry handle