The detection algorithm should be good enough for that case now.

Move the writing of include directives into the generated header into 
header.c.

widl: Make the rules for parsing fields in structures, encapsulated unions and non-encapsulated unions more strict.

Move the rules in fields that handle empty union cases into separate 
union rules so that they can't erroneously be accepted for structures or 
other types of unions.

This allows arrays to be used in typedefs and const statements.