Move clang-format file into root directory

[devreal]

This PR will make our .clang-format rules more visible and easier to use (clang-format is looking for that file in the current directory or any parent directory)

[codecov]

Codecov Report

Merging #602 into development will not change coverage.
The diff coverage is n/a.

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##           development     #602    +/-   ##
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  Coverage        84.95%   84.95%            
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  Files              316      316            
  Lines            24159    24159            
  Branches         11513    11109   -404     
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  Hits             20524    20524            
  Misses            3634     3634            
  Partials             1        1

[fmoessbauer]

Another two files in the root directory... For what reason did we have the contrib folder?
@rkowalewski : I guess there was once a discussion to move the dev-only stuff to this folder?

[devreal]

Right now the contrib folder only contains these two files, hidden. For new users (or developers not aware that we have a clang-format stylefile) it's virtually invisible...

[rkowalewski]

I guess there was once a discussion to move the dev-only stuff to this folder

Yup. The original intent was that we do not want to "pollute" our root directory with files which are not a required part of our toolchain. I am also not aware that everybody uses clang-format. So I used this approach as other projects do it in a similar way. We deleted also the .syntastic_*files for that reason.

But for me it's fine that we move it to the root directory and we should definitely use a common formatting. @pascalj and me are using this one in the repository and it is quite pretty. If you have some suggestion feel free to change it.

[rkowalewski]

In my opinion we can move some of the build.* files into the contrib folder. The most relevant are build.minimal.sh, build.dev.sh and build.sh. I think almost nobody uses the other files.

[rkowalewski]

small update to our .clang-format. The settings are based on Google and I just added the relevant customizations for our code base. This way, our config is easier to maintain and gets new features without explicitly adding it in our config.