* Grammar: add exec statement; allow testlist in expr statement.
* ceval.c, compile.c, opcode.h: support exec statement;
avoid optimizing locals when it is used
* fileobject.{c,h}: add getfilename() internal function.
Added $(SYSDEF) to its build rule in Makefile.
* cgensupport.[ch], modsupport.[ch]: removed some old stuff. Also
changed files that still used it... And made several things static
that weren't but should have been... And other minor cleanups...
* listobject.[ch]: add external interfaces {set,get}listslice
* socketmodule.c: fix bugs in new send() argument parsing.
* sunaudiodevmodule.c: added flush() and close().
(1) dictionaries/mappings now have attributes values() and items() as
well as keys(); at the C level, use the new function mappinggetnext()
to iterate over a dictionary.
(2) "class C(): ..." is now illegal; you must write "class C: ...".
(3) Class objects now know their own name (finally!); and minor
improvements to the way how classes, functions and methods are
represented as strings.
(4) Added an "access" statement and semantics. (This is still
experimental -- as long as you don't use the keyword 'access' nothing
should be changed.)