failures gracefully

From SF patch #852334.

unique boundary strings within a program run are guaranteed.  On Windows,
duplicates were pretty likely, due to the coarse granularity of time.time.
Toned down the absurdly optimistic claims in the docstring.

Bugfix candidate.

Weinberg).  This changes all uses of deprecated tempfile functions to
the recommended ones.

getuid or getpid.  posix_getuid & posix_getpid never raise exceptions when
called with no args.

will not have been done, and applications need to know that.  Also, do
not print a message about it; the exception is the right thing.

This closes SF bug #133717.

test___all__.py: fail silently in check_all if the module can't be imported

Use != instead of <> since <> is documented as "obsolescent".
Use "is" and "is not" when comparing with None or type objects.

recognize the '7bit' and '8bit' encodings, to simplify use.

who writes:

Here is batch 2, as a big collection of CVS context diffs.
Along with moving comments into docstrings, i've added a
couple of missing docstrings and attempted to make sure more
module docstrings begin with a one-line summary.

I did not add docstrings to the methods in profile.py for
fear of upsetting any careful optimizations there, though
i did move class documentation into class docstrings.

The convention i'm using is to leave credits/version/copyright
type of stuff in # comments, and move the rest of the descriptive
stuff about module usage into module docstrings.  Hope this is
okay.

of the boundary chosen by choose_boudary() by using milliseconds
of the timestamp.

to decode/encode the standard transfer encodings.

parameters of the content-type header.

  constructors.  There is no backward compatibility.  Not everything has
  been tested.
* aiff.{py,doc}: deleted in favor of aifc.py (which contains its docs as
  comments)

* Fixed calendar.py, mimetools.py, whrandom.py to cope with time.time()
  returning a floating point number.  (And fix old bug in calendar)
* Add recursion level to mainloop.mainloop(), to make it reentrant.

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