Unfortunately, gir marks all integers as gint regardless
of its size. We have to check if the value will really
fit into a int, that is why there is an automatic fallback
to long.
Bundle Options.cs from the Mono source tree, and use it to parse the
command-line options for gapi-codegen. This gives us clearer code,
descriptions for each option, and a nice "--help" output.
This does not change the options syntax, except that -I|--include needs
to specified for each file to include. Two Makefiles in sample/ are
updated for that change.
