remove hard-coded logic for discriminating btw two duration distributions about alignmentduration HOT 4 CLOSED

Either in StateWithDur or Phoneme or _DurationHMM (best here) put field which duration distrib. to use.

BACKGROUND: For exponential disrib. there is no duration, but there is transprob. and only middle state instead of three. (because I dont know how to implement the 3 states with exponential distrib.)

PROBLEM:

1. hard coded sil on first and last phoneme has only middle state in LyricsWithModels.LyricsWithModels._linkToModels

2. hard coded on first and last state there is expo distrib in hmm.continuous._DurationHMM._DurationHMM.getWaitLogLik

3. set distrib type in Lyrics.Lyrics._words2Phonemes

from alignmentduration.

as well HARD CODED in
LyricsWithModels.LyricsWithModels.duration2numFrameDuration

from alignmentduration.

as well hard coded in
Decoder.decodeAudio()
# transMatrix for 0 state which is silence
transMatrix = self.lyricsWithModels.phonemesNetwork[0].getTransMatrix()
self.hmmNetwork.setWaitProbSilState(transMatrix[2,2])

from alignmentduration.

remove setDurationInMinUnit from Phoenems class. Phoenmes is assigned directly a durInFrames

rewrite its only reference (from Lyrcis._words2Phonemes) in a more clever way:
phonemeSil.setDurationInMinUnit('1')

from alignmentduration.