Version generated files

[JonasVautherin]

@thomasetter: FYI

• Generate protobuf and gRPC source files from a script (instead of doing it in the cmake configure step)
• Version those generated files

Resolves #816.

[JonasVautherin]

hmm not passing the style checks. @julianoes: do you know if there is a way to ignore a directory in fix_style.sh? I see some style_ignore logic but I'm not sure I completely get it 😕.

[julianoes]

@JonasVautherin it looks like the style-ignore.txt file was removed at some point. I've added it back and it seems to work.

[JonasVautherin]

Ubuntu 14.04 with gcc6 is failing for an obscure reason 😅.

[julianoes]

Yer I've seen this in other places. It's the coveralls thing, maybe because coveralls was down or being maintained: https://status.coveralls.io/.