Join the license header with historical comments using a separator so IDEs can correctly parse the initial header.
Also use .gitattributes to ensure all files are LF.
The MACINTOSH define refers to MacOS Classic (not OS X) which we do not
plan to support. Rather than carry the cruft forever, let's delete it.
NOTE: legacy/ is unused but we're keeping it around, so MACINTOSH uses
there are left alone.
Process used for this commit:
```
git rm -r mac
find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" \) \
-exec unifdef -UMACINTOSH -o {} {} \;
git restore legacy
git add .
```
Test Plan:
On Mac, build both Debug and Release
```
cmake --build --preset mac --config Debug
cmake --build --preset mac --config Release
```
sound_seg was -1, which crashes in BOA_INDEX(sound_seg) on 64bit
platforms (by pure luck it doesn't seem to crash on 32bit platforms)
It makes sense to catch this problem much earlier in Play3dSound(),
to avoid executing all the superfluous
Most of the warnings were caused by uninitialized values. Some were in plug-ins that didn't have a break in a switch, causing the memory to be deleted twice.
