labels - add writeHtkLabFile method

Ignore-this: 9a9abb2a306aa7f21717ec016a3544a9

darcs-hash:20130621140926-3a4db-48b2ab17d0c63c63fd0deb910fb8617783a0c166
(experiment - fix drawLabelledSeq option that was changed)

Ignore-this: e381d9c6cf835bade66165344aff4d5c

darcs-hash:20130624230212-3a4db-0926babe22208f8fe4cc9673fda4296eb35666b4
dist - add hardMean flag to MixtureDist to allow better control of meanish synthesis

Ignore-this: 25a5063d64668d271c58ed1fe81b5044

darcs-hash:20130710154514-3a4db-32917380593a9a7e7c063198ffa411961b21fa69