Added support for “file” extensions
Parsing XML file package to detect the files to backup
Fixed target path for file packages
Fixed xpath for files
Added support for libraries, too
Consider element inside the <file> tag, too
Added support for media tag inside the manifest file
Add support for packages
Scan package manifest file, analyzing every entry
Added support for packages, too
Updated link template file.

Close #464
Merge pull request #467 from akeeba/feature/464-improve-srp

Feature/464 improve srp