IDL conventions

[Minor Gordon]

Hello all,

We've had some problems recently with .idl modifications that don't
quite fit our conventions: using Java instead of C naming conventions,
spacing issues, breaking alphabetical order, etc. It's not a big deal
when it happens, but over time these things tend to accumulate and
make our interfaces more difficult to understand than they need to be.

Part of the problem is that only a few people are aware of what our
IDL should look like. As a remedy for this I've written up our .idl
coding conventions in a simple text document, doc/idl_conventions.txt.
In the future please familiarize yourselves with the conventions
before you make changes to the interfaces.

Regards,
Minor