I ran this script in the include directory:
```sh
sed -i '' -e 's,#include "\(SDL.*\)",#include <SDL3/\1>,' *.h
```
I ran this script in the src directory:
```sh
for i in ../include/SDL3/SDL*.h
do hdr=$(basename $i)
if [ x"$(echo $hdr | egrep 'SDL_main|SDL_name|SDL_test|SDL_syswm|SDL_opengl|SDL_egl|SDL_vulkan')" != x ]; then
find . -type f -exec sed -i '' -e 's,#include "\('$hdr'\)",#include <SDL3/\1>,' {} \;
else
find . -type f -exec sed -i '' -e '/#include "'$hdr'"/d' {} \;
fi
done
```
Fixes https://github.com/libsdl-org/SDL/issues/6575
* Add changes from code review by @ccawley2011, #5597, overall cleanup
* Update N-Gage README, minor cleanup and rephrasing
* Call SDL_SetMainReady() before calling SDL_main, return SDL_main instead of main
* Add initial support for the Nokia N-Gage
* N-Gage: disable clipping for the time being, issue needs to be resolved later
* Move va_copy definition to SDL_internal.h
* Move stdlib.h include to SDL_config_ngage.h, much cleaner this way
* Remove redundant include, add HAVE_STDLIB_H
* Revert "N-Gage: disable clipping for the time being, issue needs to be resolved later"
This reverts commit 4f5f0fc36c.
* N-Gage: fix clipping issue by providing proper math functions
