Code formatting rules

[Vavat]

@Netzpfuscher, hi. David asked me to have a chat with you regarding code clean up. He's aware that he writes horribly formatted code and wanted to pull some resource to have code a bit more maintainable. Since you are a very active contributor, I thought it makes sense to have a discussion with you first before anything is done to find out your opinion and preferences.
I suggest that this issue be dedicated to ironing out two questions:

• format of the code that we should strive towards
• manner in which changes to the code formatting should be made

Under format of the code I mean things like naming convention for variables, functions, constants, etc. #define vs. static const. Tab vs. spaces. Brace position. Once those decisions are made quite a bit of that can be automated.

As far as implementation goes I see two options: wait until code reaches reasonable stability and do entire codebase in one hit, or introduce rules and enforce them with every merge request, thus allowing code to morph into acceptable format gradually. I am not sure how confident you are with code stability and whether David and you are happy to stop development to do all changes in one. It introduces certain difficulties in tracing bugs back beyond the formatting changes since diffing becomes much trickier. If this was production grade code for a commercial enterprise I would advocate gradual changes. This is where your input is paramount.

Let me know what you think.