use log10() to calculate the size of the output array. The current code
has been tested on x86/amd64 (and to a lesser extent on qemu-mips qemu-sparc)
and produces sufficiently large values for all inputs tested so far (coefficient
sizes of 10**18 - 1 are hard to test exhaustively).

The new code does not rely on the correctness of log10() and resizes
the output arrays if the allocated space is insufficient.

Patch by Marc Abramowitz.

  AC_PATH_PROG and AC_CHECK_PROGS for the target tools.

  global host_platform instead.

the Ctrl-C signal handler on Windows

the Ctrl-C signal handler on Windows

Patch by Serhiy Storchaka.

Patch by Serhiy Storchaka.

Patch by Jakub Wilk.

Patch by Jakub Wilk.

Now that rmdir supports dir_fd, we also use it. Attackers can't even delete
empty directories anymore.

If messages were only added, a new file is no longer created and
renamed over the old file when flush() is called on an mbox, MMDF or
Babyl mailbox.

If messages were only added, a new file is no longer created and
renamed over the old file when flush() is called on an mbox, MMDF or
Babyl mailbox.

Also added several regression tests.

os.urandom() has now one unique implementation, posix_urandom() which
calls _PyOS_URandom(). _PyOS_URandom() uses RAND_pseudo_bytes() on VMS.