Removed the need for libSDL2main.a on Android, and separated JNI initialization out for other integrations

configure.in

@@ -3201,7 +3201,6 @@ case "$host" in
                 ANDROID_CFLAGS="-DGL_GLEXT_PROTOTYPES"
                 CFLAGS="$CFLAGS $ANDROID_CFLAGS"
                 SDL_CFLAGS="$SDL_CFLAGS $ANDROID_CFLAGS"
-                SDL_LIBS="$SDL_LIBS -lSDL2main -Wl,-u,SDL_main_dummy"
                 EXTRA_CFLAGS="$EXTRA_CFLAGS $ANDROID_CFLAGS"
                 EXTRA_LDFLAGS="$EXTRA_LDFLAGS -ldl -lGLESv1_CM -lGLESv2 -llog -landroid"
                 SDLMAIN_SOURCES="$srcdir/src/main/android/*.c"