Changes applied:
* Moved utility files to /util/.
* Removed unused #includes.
* Removed unused ::ffmpeg::tools function.
* Removed unused variables.
* Fixed missing parentheses in the version macro.
* Fixed missing override on virtual function overrides and removed unnecessary virtual keyword from them.
* Disabled additional warning for ATL headers on MSVC only.
* Replaced direct printf parameters with their macro equivalent.
* Replaced C-style casts with C++-style casts.
* Applied clang-format again after an earlier change to the CMake file broke the integration for it.
The number of files in the source directory was a little bit much and just made file naming more complex than it had to be. Therefore all files were moved into subdirectories where it matters.
Filters now reside in source/filters/, Sources in source/sources/, OBS Wrappers in obs/, OBS GS Wrappers in obs/gs/, Transitions will reside in source/transitions, Graphics Helpers will be in gfx/.
