Release iText 5.5.12

iText 5.5.12 is a maintenance release that rolls up 22 bugfixes for iText 5 Core from the past 5 months. At the same time we also released pdfXFA 1.0.2, an add-on for iText 7. All bugfixes for XFAWorker 5.5.12 were ported to pdfXFA 1.0.2.