Add more robust clang-format executable

[cacharle]

Right now, we're using a clang-format executable for both Linux and Mac to have the same version of clang-format no matter what version of it is installed on the user's system.

But this is causing issues with dynamic linking since different version can link to different .so.

#17 (comment)

We should find a way to either build a standalone clang-format executable or include the needed shared libaries with the c_formatter_42 package.

[cacharle]

http://www.linuxmisc.com/9-unix-programmer/8793219ab1f00856.htm
https://stackoverflow.com/questions/19425993/how-to-convert-dynamic-executable-to-static-executable

Have to recompile apparently.

[cacharle]

Dynamic linking stuff can be avoided if we have an executable by OS and architecture (only supports x86_64 right now