Add extremely basic unit test framework.

tests/UnitTest.h

@@ -0,0 +1,14 @@
+#ifndef TELODENDRIA_UNITTEST_H
+#define TELODENDRIA_UNITTEST_H
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST(body) int main(void) { body; return 0; }
+
+#define ASSERT(condition) if (!(condition)) { \
+	printf("%s:%d: Assertion failed: %s\n", __FILE__, __LINE__, #condition); \
+	exit(1); \
+}
+
+#endif