text_reader.fsm: model the FSM in text_reader.cpp

This change:

1.  Defines a YAML-based language for describing Finite State
    Machines.

2.  Uses that language to describe the FSM in
    src/libcainteoir/tts/text_reader.cpp

3.  Creates a tools/fsm program to generate a DOT file from a
    FSM data file.

4.  Defines Makefile rules for generating an SVG file of the FSM
    when 'make fsm' is run.

5.  Remove the old data/parsetext-fsm.dot file that described the
    old FSM before the change to using Unicode General Categories.
autotools: merge the phonemes target into documentation, and the .phon rule into tools/extensions