minimal fixes to visual test, so that it actually builds w/o warnings:

- linux_process.c: add an SDLVisualTest_ScreenshotProcess() stub for
  linux builds succeed.
- action_configparser.c: fixes -Wswitch warnings.
- testharness.c: fixes 'is used uninitialized' warnings for userevents.
- testharness.c: fixes format string argument to 'Force killing...'
- testquit.c: fix type of options array in main().
- windows_screenshot.c: lowercase windows.h header name.
- ran dos2unix on all sources and add missing newlines at files' ends.
- minor adjustments to autotools build system (which actually seems to
  need more surgery for unnecessary stuff...)

visualtest/unittest/testquit.c

@@ -64,7 +64,7 @@ main(int argc, char** argv)
 
         if(consumed < 0)
         {
-            static const char *options = { "[--exit-code N]", "[--crash]", "[--hang]", NULL };
+            static const char *options[] = { "[--exit-code N]", "[--crash]", "[--hang]", NULL };
             SDLTest_CommonLogUsage(state, argv[0], options);
             SDLTest_CommonQuit(state);
             return 1;