Get Cosmopolitan into releasable state

A new rollup tool now exists for flattening out the headers in a way
that works better for our purposes than cpp. A lot of the API clutter
has been removed. APIs that aren't a sure thing in terms of general
recommendation are now marked internal.

There's now a smoke test for the amalgamation archive and gigantic
header file. So we can now guarantee you can use this project on the
easiest difficulty setting without the gigantic repository.

A website is being created, which is currently a work in progress:
https://justine.storage.googleapis.com/cosmopolitan/index.html

libc/runtime/assertfail.c

@@ -48,7 +48,7 @@ relegated void __assert_fail(const char *expr, const char *file, int line) {
     p = mempcpy(p, expr, exprlen);
     p = stpcpy(p, "\r\n");
     write(STDERR_FILENO, msg, p - msg);
-    if (weaken(die)) weaken(die)();
+    if (weaken(__die)) weaken(__die)();
   }
   abort();
   unreachable;