This changes to use 'transfer' to make clear that the reference count is
unchanged. Some think that the previous wording 'take' is good as-is;
some agree with me. Daniel Dragan has pointed out that 5 years ago I
changed this line, while retaining 'take'. Given that 'transfer' is
unambiguous to all, while 'take' is ambiguous to some, I'm making the
change.
/*
=for apidoc av_push
-Pushes an SV onto the end of the array. The array will grow automatically
-to accommodate the addition. This takes ownership of one reference count.
+Pushes an SV (transferring control of one reference count) onto the end of the
+array. The array will grow automatically to accommodate the addition.
Perl equivalent: C<push @myarray, $elem;>.