segfault in _rl_accel.c

Neil Schemenauer (https://bitbucket.org/nascheme/) has found and debugged a 
segfault in the accelerator (see 
https://bitbucket.org/rptlab/reportlab/issues/78/use-after-free-bug-in-_rl_accel-unicode2t1).

I have applied Neil's patch and tested. It doesn't seem to cause any untoward 
effects, but since I was not seeing the problem before on my main development 
platform (win32/win64) I cannot tell if it actually does the job.

I have released the patched version as 3.3.7

3a78e2dd84502ae967ba3bf9aeb08f0b59edc032

if nobody complains loudly in the next few days I will push this to pypi 
sometime next week.
-- 
Robin Becker