Support the (transfer) annotation for properties.

* girepository/*: Add g_property_info_get_ownership_transfer() and write
  the transfer attribute of properties into the typelib.

* giscanner/*: Parse the (transfer) annotation and write it into the .gir.

* tools/generate.c: Read the transfer annotation for properties and write
  to the .tgir.

https://bugzilla.gnome.org/show_bug.cgi?id=620484