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

third_party/stb/stb_image.c

@@ -35,6 +35,8 @@
 #include "third_party/stb/internal.h"
 #include "third_party/stb/stb_image.h"
 
+#define ROL(w, k) ((w) << (k) | CheckUnsigned(w) >> (sizeof(w) * 8 - (k)))
+
 asm(".ident\t\"\\n\\n\
 stb_image (Public Domain)\\n\
 Credit: Sean Barrett, et al.\\n\