irteus/test/geo.l: add test code for geometry functions (https://github.com/euslisp/EusLisp/pull/21)
owverwrite face-normal-vector, see https://github.com/euslisp/EusLisp/pull/21
Merge pull request #100 from k-okada/add_geo_test

irteus/test/geo.l: add test code for geometry functions