Add support for TH transducer

[aaronfay]

Repo is here: https://github.com/giellalt/lang-cwd

[danielfay]

I've successfully built lang-cwd by following the README, but with a couple additions and notes I'll add here:

Before installing their recommended packages, more fundamental ones are probably missing, I ran:

sudo apt-get install autoconf automake libtool pkg-config build-essential

and it seemed to cover all the bases.

Then they recommend:

wget https://apertium.projectjj.com/apt/install-nightly.sh -O - | sudo bash
sudo apt-get install cg3 hfst

Then you can checkout and run these commands in the lang-* repo, though note autogen.sh will pull two more repos into the folder where you cloned the lang-* repo as their comment notes.

./autogen.sh # This will automatically clone or check out other GiellaLT dependencies
./configure
make

After the make is finished the FST files can be found in src/fst