gir: Add object documentation and `Since` tag to the generated gir file
Fix gen-api-gtkdoc.py
to also parse a structs detailed description, which may contain a \since
attribute,
and to generate a gtkdoc definition for those structs in the output wp-gtkdoc.h
.
This makes the structs documentation and Since
attribute end up in the final .gir
file.
Fixes #497 (closed).
Edited by Tom Wagner