Make fixes, improvements, and chibicc python bindings

- python now mixes audio 10x faster
- python octal notation is restored
- chibicc now builds code 3x faster
- chibicc now has help documentation
- chibicc can now generate basic python bindings
- linenoise now supports some paredit-like features

See #141

libc/mem/arena.h

@@ -0,0 +1,11 @@
+#ifndef COSMOPOLITAN_LIBC_MEM_ARENA_H_
+#define COSMOPOLITAN_LIBC_MEM_ARENA_H_
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+void __arena_push(void);
+void __arena_pop(void);
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_MEM_ARENA_H_ */