Updated Tika (Load File Contents) PDI step to 1.1

This update does the following:

1) Migrate from Ant/Ivy/Subfloor to Gradle
2) Update Tika from 1.3 to 1.6
3) Workaround (for local files only) for a VFS bug that closes the stream when reading some files < 64KB (PDFs, e.g.)