Update Extra.pm

avoid: 

given is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 119.
when is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 120.
when is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 121.
when is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 122.
given is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 140.
when is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 141.
when is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 142.
when is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 143.
given is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 159.
when is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 160.
when is experimental at /usr/local/share/perl/5.18.2/App/Cope/Extra.pm line 161.
 on newer version of perl