Add PerlLicense crawler that could look for license file on Metacpan filelist

[timgluz]

Some, specially older, Perl packages have no license information, but if you look into their file directory, there usually exists license file. Quite many of them are using a name Artistic;

Also research how those old packages refer to dependencies;

Here's example for Curses: https://metacpan.org/source/GIRAFFED/Curses-1.36

[timgluz]

It would be useful to dig into data hosted on mirrors: https://metacpan.org/mirrors#Germany