The EN DASH is not really required in year ranges such as 2012–2015 when
we're talking about comments in source code that is probably being
displayed in a fixed font anyway. Changing back to an ordinary hypen
allows us to make a meaningful test for use utf8.
This command was used:
find . -type f -print0 | xargs -0 sed -i 's/return undef/return/g'
The idea behind this commit is described on http://oddmuse.org/wiki/Refactoring page.
In short: 'return undef' returns (undef) in list context (a list with one element),
which is wrong.
