Revision history for Perl extension if.
0.01 The version of 5.7.3.
0.010001 `our' removed for backward-compatibility.
test adopted for backward-compatibility
0.04 support package names which are simultaneously keywords (open).
fix `require or die'.
0.05 Sync with perl5.12.2:
Better error handling.
Suggest significance of => in the docs.
0.06 Update email address.