librnd 2.4.0
~~~~~~~~~~~~

Mainly a bugfix release with an API change for a broken (non-portable)
data conversioin fix:

1. API CHANGE: remove ->value field from export options; export options
   should be const and current values should be maintained in
   hid->argument_array; this fixs a bug caused by unknown sizeof(enum) vs.
   sizeof(void *)

2. Many smallish, random bugfixes, mostly on the gtk side