This formats all copyright comments according to SPDX formatting guidelines.
Additionally, this resolves the remaining GPLv2 only licensed files by relicensing them to GPLv2.0-or-later.
Adds missing includes to prevent potential compilation issues in the
future. Also moves the definition of a struct into the cpp file, so that
some includes don't need to be introduced within the header.
Specifically bugs/crashes that arise when putting them in positions that are legal but not typical, such as midline, between patch data, or between patch records.
