by special syntax: you can now define your own numbers, sequences and
mappings.

posixpath.py: added undocumented expanndvars() (expands $VAR in string).

posixmodule.c: waitpid() is separate

added gettext() method to TextEdit.py;
fixed string.atoi() to ignore leading zeros.

* socketmodule.c: get rid of makepair(); fix makesocketaddr to fix
  broken recvfrom()
* socketmodule: get rid of getStrarg()
* ceval.h: move eval_code() to new file eval.h, so compile.h is no
  longer needed.
* ceval.c: move thread comments to ceval.h; always make save/restore
  thread functions available (for dynloaded modules)
* cdmodule.c, listobject.c: don't include compile.h
* flmodule.c: include ceval.h
* import.c: include eval.h instead of ceval.h
* cgen.py: add forground(); noport(); winopen(""); to initgl().
* bltinmodule.c, socketmodule.c, fileobject.c, posixmodule.c,
  selectmodule.c:
  adapt to threads (add BGN/END SAVE macros)
* stdwinmodule.c: adapt to threads and use a special stdwin lock.
* pythonmain.c: don't include getpythonpath().
* pythonrun.c: use BGN/END SAVE instead of direct calls; also more
  BGN/END SAVE calls etc.
* thread.c: bigger stack size for sun; change exit() to _exit()
* threadmodule.c: use BGN/END SAVE macros where possible
* timemodule.c: adapt better to threads; use BGN/END SAVE; add
  longsleep internal function if BSD_TIME; cosmetics

Also, get rid of makepair() in favor of mkvalue().

* split pythonmain.c in two: most stuff goes to pythonrun.c, in the library.
* new optional built-in threadmodule.c, build upon Sjoerd's thread.{c,h}.
* new module from Sjoerd: mmmodule.c (dynamically loaded).
* new module from Sjoerd: sv (svgen.py, svmodule.c.proto).
* new files thread.{c,h} (from Sjoerd).
* new xxmodule.c (example only).
* myselect.h: bzero -> memset
* select.c: bzero -> memset; removed global variable

* select.c: bzero -> memset; removed global variable

Minor, minor changes to commands.py and sndhdr.py.

Got rid of old module 'localtime.py'.

>   added 'clobber' target