Investigate whether other aligners can be integrated/wrapped

[pettarin]

For example:

gentle (based on Kaldi) : https://lowerquality.com/gentle/ Prosodylab-Aligner (based on HTK) : http://prosodylab.org/tools/aligner/

[readbeyond]

Testing other approaches, like GMM/HMM/NN (e.g., using HTK or Kaldi)