- add cmd line parameter to set temp directory
- find_mislabels: don't call RAxML subtreeEPA if there are no higher ranks to test (used to exit with error)
epa_trainer: allow to ignore non-standard number of ranks
fix bug in placements in case if all ranks are empty
find_mislabels: do not assume that taxonomy always has 7 levels; instead, try to guess level names using simple heuristic