Improve Libc by making Python work even better

Actually Portable Python is now outperforming the Python binaries
that come bundled with Linux distros, at things like HTTP serving.
You can now have a fully featured Python install in just one .com
file that runs on six operating systems and is about 10mb in size.
With tuning, the tiniest is ~1mb. We've got most of the libraries
working, including pysqlite, and the repl now feels very pleasant.
The things you can't do quite yet are: threads and shared objects
but that can happen in the future, if the community falls in love
with this project and wants to see it developed further. Changes:

- Add siginterrupt()
- Add sqlite3 to Python
- Add issymlink() helper
- Make GetZipCdir() faster
- Add tgamma() and finite()
- Add legacy function lutimes()
- Add readlink() and realpath()
- Use heap allocations when appropriate
- Reorganize Python into two-stage build
- Save Lua / Python shell history to dotfile
- Integrate Python Lib embedding into linkage
- Make isregularfile() and isdirectory() go faster
- Make Python shell auto-completion work perfectly
- Make crash reports work better if changed directory
- Fix Python+NT open() / access() flag overflow error
- Disable Python tests relating to \N{LONG NAME} syntax
- Have Python REPL copyright() show all notice embeddings

The biggest technical challenge at the moment is working around
when Python tries to be too clever about filenames.

libc/sysv/consts/termios.h

@@ -12,7 +12,6 @@ extern const long BUSY;
 extern const long CANBSIZ;
 extern const long CBAUD;
 extern const long CBAUDEX;
-extern const long CEOL;
 extern const long CIBAUD;
 extern const long CLOCAL;
 extern const long CMSPAR;
@@ -35,6 +34,8 @@ extern const long ECHOKE;
 extern const long ECHONL;
 extern const long ECHOPRT;
 extern const long ENDRUNDISC;
+extern const long EXTA;
+extern const long EXTB;
 extern const long EXTPROC;
 extern const long FF1;
 extern const long FF2;
@@ -222,7 +223,6 @@ COSMOPOLITAN_C_END_
 #define CANBSIZ          SYMBOLIC(CANBSIZ)
 #define CBAUD            SYMBOLIC(CBAUD)
 #define CBAUDEX          SYMBOLIC(CBAUDEX)
-#define CEOL             SYMBOLIC(CEOL)
 #define CIBAUD           SYMBOLIC(CIBAUD)
 #define CLOCAL           SYMBOLIC(CLOCAL)
 #define CMSPAR           SYMBOLIC(CMSPAR)
@@ -241,6 +241,8 @@ COSMOPOLITAN_C_END_
 #define ECHONL           SYMBOLIC(ECHONL)
 #define ECHOPRT          SYMBOLIC(ECHOPRT)
 #define ENDRUNDISC       SYMBOLIC(ENDRUNDISC)
+#define EXTA             SYMBOLIC(EXTA)
+#define EXTB             SYMBOLIC(EXTB)
 #define EXTPROC          SYMBOLIC(EXTPROC)
 #define FLUSHO           SYMBOLIC(FLUSHO)
 #define H4DISC           SYMBOLIC(H4DISC)