Add files from https://github.com/intranda/goobi-plugin-opac-pica
Move plugin into package org.goobi.production.plugin.opac
Change configuration
Using operating system independent file separator
Removing PluginInfo CLI application and dummy plugins.txt (dead code)
Create “plugins” directory structure, add PicaOpacImport plugin jar,
update description
Bug fix for Bug #1233136

The task of calculating the ATS or—in absence of an author—the TSL is a
trivial task which doesn’t depend on anything else than those two
strings. There is no need to define this function in an interface and
implement it over and over again in various plugins.

• Added public static method to ProzesskopieForm
• Rewrote method for better readability and to use StringBuilder
(faster)
• Corrected CalcProzesstitel() to work without catalogue
• Removed unnecessary method from interface IOpacPlugin
• Removed unnecessary method from PicaOpacImport source
• Updated picaOpacImportClass.jar in plugins directory
Merge branch 'import-pica-plugin' into united-changes
Merge branch 'bug-1233136' into united-changes