Add nmc_node_children macro
Assert(false) instead of return NULL in private_node_free
Clean up asprintf.c and vasprintf.c
Use api.pure full
Move output initialization to main
Namespace node types
Namespace node_type
Namespace node_name
Simplify failure handling in nmc_node_xml
Remove unnecessary entries in xml types table
Use UAX#29 for correct handling of emphasis end
Use WordBreakProperty.txt instead of hand-made property check
Implement u_word_break and test it

This function won’t be needed, it seems, but it was a good exercise.
I’m happy with the solution to the problem.  No one seems to have
implemented it using a state table before.
Update word/inline termination/start handling