Non-matching calls to PyErr_Fetch/Restore cause a leak in v3.12,
so ensure calls are symmetrical or avoid where possible.
Simplify extraction of the exception buffer.
- Only overwrite the stderr (the stdio isn't used).
- Simplify pyc_exception_buffer_handle_system_exit usage.
- Remove goto's.
Also simplify calling conventions for PyC_ExceptionBuffer functions.
- They must be called when an error has occurred.
- Always return a string, never null since a null return value would
only happened in rare/unexpected cases which wasn't being checked
for by some callers, leading to potential crashes.
Listing the "Blender Foundation" as copyright holder implied the Blender
Foundation holds copyright to files which may include work from many
developers.
While keeping copyright on headers makes sense for isolated libraries,
Blender's own code may be refactored or moved between files in a way
that makes the per file copyright holders less meaningful.
Copyright references to the "Blender Foundation" have been replaced with
"Blender Authors", with the exception of `./extern/` since these this
contains libraries which are more isolated, any changed to license
headers there can be handled on a case-by-case basis.
Some directories in `./intern/` have also been excluded:
- `./intern/cycles/` it's own `AUTHORS` file is planned.
- `./intern/opensubdiv/`.
An "AUTHORS" file has been added, using the chromium projects authors
file as a template.
Design task: #110784
Ref !110783.