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

tool/emacs/cosmo-c-builtins.el

@@ -1289,8 +1289,7 @@
            "isconstant"
            "chooseexpr"
            "likely"
-           "unlikely"
-           "assume"))
+           "unlikely"))
 
 )
     (concat "\\_<"

tool/emacs/cosmo-c-keywords.el

@@ -124,8 +124,7 @@
         ;;    "delete"))
 
         (cosmo
-         '("__rbx"
-           "__msabi"
+         '("__msabi"
            "offsetof"
            "microarchitecture"
            "targetclones"