Fixes several files incorrectly stated a different license from the actual project, as well as the copyright headers included in all files. This change has no effect on the licensing terms, it should clear up a bit of confusion by contributors. Plus the files get a bit smaller, and we have less duplicated information across the entire project.
Overall the project is GPLv2 if not built with Qt, and GPLv3 if it is built with Qt. There are no parts licensed under a different license, all have been adapted from other compatible licenses into GPLv2 or GPLv3.
A complete redesign of the component and dependency system is necessary in order to support additional platforms, such as MacOS and other Linux platforms. Additionally it results in a much cleaner code base, which is less confusing overall.
Eventually it might be necessary to push components of StreamFX into their own CMake projects, as it is getting kind of complex now. Especially with the push for a proper plugin manager, things get dicey for big plugins like StreamFX.
