added avx/avx options via ROLLOPTS
changed AVS_FLAG to AVX_FLAG
changed the logic flow in the AVX test
Merge pull request #1 in APS/raxml-roll from feature/APS-32-add-rollopt-to-raxml to master

* commit 'dbc86fe4724183ceda7512c0bd1592d9f577949c':
  changed the logic flow in the AVX test
  changed AVS_FLAG to AVX_FLAG
  added avx/avx options via ROLLOPTS