Full UTF-8 validity check in Markov. Markov mode now works pretty good with
UTF-8 provided you use -p with calc_stat and --enc:utf8 with Markov mode.
Revert "expose markov stats file as command line option"

This reverts commit 7c9899fab54e9f27e9a30c6ef49584acae868589.

The patch broke normal --markov use.