Visual Studio projects doesn't mark "protocol.fbs" as "Custom Build Tool".

[forrestthewoods]

Kinda similar to issue #4.

Visual Studio projects currently mark protocol.fbs as "Does not participate in build". It needs to be marked as "Custom Build Tool". If it's "Custom Build Tool" then Visual Studio correctly runs a pre-build step to re-generate flatbuffer code. Dependent projects correctly update only when the generated code changes.

Everything works exactly right if you open a solution and manually make the change.

Now I just need to figure out how to get GENie to generate a solution with this fix. It probably requires an update to GENie itself. One I'm happy to make as soon as I figure out how to also do the gmake equivalent for issue #4.