Fixed broken bonobo build

[Maciej Stachowiak <mjs eazel com>]

I checked in some changes to Bonobo (in the bonobo-idl directory)
because it wasn't compiling for me or anyone else I asked. I didn't
send a patch or wait for approval because, well, the build was
broken. I hope no one minds this breach of ettiquette.

 - Macirej