Committing Dr Bainbridge's improvements to the Tika-preconfigured UnknownConverterPlugin: 1. Introducing the OS-agnostic %%GSDLHOME variable into the model collConfig.xml file which the UnknownConverterPlugin.pm will replace with or %GSDLHOME% as needed. The perl file will now also handle GSDL3HOME and GSDL3SRCHOME similarly. 2. The tika-app-1.24.1.jar is now renamed to just tika-app.jar so that UnknownConverterPlugin's exec_cmd works on Windows too, where there is no file globbing or wildcard to expand tika-app*.jar as there was on Linux. The gs2build/ext/tika folder's README has been updated to mention the version number of the tika-app jar file we're using.