Merge Py Idle changes:

Merge Py Idle changes:
Rev 1.5 tim_one
Convert a pile of obvious "yes/no" functions to return bool.

Rev 1.6 gvanrossum
(partially merged previously, move line outside try: block)

Provisional fix for writefile() [SF bug # 541730].

The problem was that an exception can occur in the text.get() call or
in the write() call, when the text buffer contains non-ASCII
characters.  This causes the previous contents of the file to be lost.

The provisional fix is to call str(self.text.get(...)) *before*
opening the file, so that if the exception occurs, we never open the
file.

Two orthogonal better solutions have to wait for policy decisions:

1. We could try to encode the data as Latin-1 or as UTF-8; but that
   would require IDLE to grow a notion of file encoding which requires
   more thought.

2. We could make backups before overwriting a file.  This requires
   more thought because it needs to be fast and cross-platform and
   configurable.

Rev 1.7 gvanrossum
(previously merged with modifications by Stephen M. Gava)

Add primitive printing support for Unix and Windows.

Rev 1.8 loewis
Patch #590913: PEP 263 support.

Rev 1.9 gvanrossum
(tempfile.py interface -- deferred)

Rev 1.10 tim_one
whitespace normalization

Rev 1.11 nnorwitz
(deferred pending 1.9 integration)