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.
With OBS Studio 28.0.0 a new requirement was added to MacOS plugin: Loadable Bundles. These bundles are similar to Application Bundles, and have many of the same features, but are designed to be loaded by Applications instead of being the Application. This allows for almost all of the advantages to persist, with some minimal drawbacks.
