Work around AIX shell builtin printf not handling \NNN.
On AIX, ksh builtin printf does not understand \NNN. Some tests use this
to generate test data, and so fail on AIX. Rework these tests to use python
to generate the correct characters. This fixes the tests on AIX and should
be more generally portable.
To run the tests, do:
cd tests/
python run-tests.py
See http://mercurial.selenic.com/wiki/WritingTests for
more information on writing tests.