Add retries for boost unit test timeouts.

run_boost_tests

@@ -22,16 +22,26 @@ def run_with_rerun_for_sdl_video(executable, test_name):
     # Sanity check on the number of retries.
     # It's a rare failure, a single retry would probably be enough.
     sdl_retries = 0
-    while sdl_retries < 10:
+    timeout_retries = 0
+    while sdl_retries < 10 and timeout_retries < 5:
+        sdl_retry = False
+        timeout_retry = False
+
+        try:
             res = subprocess.run([executable, "--run_test="+test_name, "--color_output"], timeout=20, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-        retry = False
+        except subprocess.TimeoutExpired as t:
+            timeout_retries += 1
+            timeout_retry = True
+            print("Test timed out, attempt", timeout_retries)
+        else:
             if b"Could not initialize SDL_video" in res.stdout:
-            retry = True
-        if not retry:
-            return res
                 sdl_retries += 1
+                sdl_retry = True
                 print("Could not initialise SDL_video error, attempt", sdl_retries)
 
+        if not sdl_retry and not timeout_retry:
+            return res
+
 if __name__ == '__main__':
     ap = argparse.ArgumentParser()
     ap.add_argument("-e", "--executable", help="The name of the boost unit test executable. Default is boost_unit_tests.", default="boost_unit_tests")
@@ -46,13 +56,7 @@ if __name__ == '__main__':
     failure=0
 
     for test in tests:
-        try:
         res = run_with_rerun_for_sdl_video(os.path.join(options.path, executable), test)
-        except subprocess.TimeoutExpired as t:
-            failure+=1
-            output = str(t.output) or ""
-            print("Test "+test+" timed out: "+output)
-        else:
         if res.returncode == 0:
             success+=1
             print("Test "+test+" passed")