Provide option to install examples with a name prefix

[StefanBruens]

Two of the examples clash with files provided by other software:

• ssdiff is a tool also provided by gnumeric
• xls2csv conflicts with http://search.cpan.org/~ken/xls2csv/script/xls2csv

[Tux]

Regarding xls2csv • https://metacpan.org/author/KEN does not mention xls2csv • https://metacpan.org/author/KEN/releases shows xls2csv as script as of 24 Sep 2005 • Mine exists in the examples since 14 Jun 2005, so I should not care (KEN could, though I doubt he will) • I'm not going to rename it. I added a note in the README regarding this possible clash • Installing is optional (though on by default as most of my users want it)

Regarding ssdiff • I didn't know • I see https://www.mankier.com/1/ssdiff shows the functionality is similar • I'll contemplate on making it support the same options • I'm not going to rename it. I added a note in the README regarding this possible clash • Installing is optional (though on by default as some of my users want it)