Apply 2to3 fixes, minus a few unnecessary list() conversions on iterators.
Branch merge: default -> py3k.
PYTHON=python3.2 in py3k Makefile.
Fix uses of deprecated TestCase.assert_ method.
bigfloat.core.set_str2 needs to encode incoming Unicode strings as ASCII.
Add extra encode-to-ascii step for internal from-string tests.
Eliminate repeated isinstance(value, str) check.
Encode to ASCII before stripping, so that we're not accepting arbitrary whitespace.
Make sure that _mpfr_get_str2 returns a string rather than bytes;  fix unicode/str-related TypeError in mpfr_get_str.
Docstring fixes: print ... -> print(...)
Fix SyntaxErrors in test_context and test_mpfr.
Fix BigFloat.__hash__ to use new Python 3 hashing algorithm.
Additional hash tests; remove comment and version test that are out of date for Python 3.
Move bytes-to-text conversions into the mpfr.py core.
Branch merge: default -> py3k.
Make mpfr_get_version and mpfr_print_rnd_mode return str, not bytes.
Make MPFR_VERSION_STRING an instance of str.
Merge removal of print statement from default branch.
Merge sys.maxint / sys.maxsize removal from default branch.
Remove unneeded _bit_length function; use int.bit_length instead.