gnu: libreoffice: Update to 5.4.5.1 [CVE-2018-6871].
* gnu/packages/check.scm (cppunit-1.14): New public variable.
* gnu/packages/libreoffice.scm (xmlsec-src-libreoffice): Remove variable.
(libreoffice): Update to 5.4.5.1.
[native-inputs]: Change CPPUNIT to CPPUNIT-1.14. Remove AUTOCONF and AUTOMAKE.
[inputs]: Add GPGME, XMLSEC-NSS and LIBLTDL. Remove XMLSEC-SRC-LIBREOFFICE.
Replace LIBJPEG with LIBJPEG-TURBO.
[arguments]: Remove xmlsec code from PREPARE-SRC-PHASE. Make sure GPGME++
headers are found. Add workaround for <https://bugs.gentoo.org/641812>. Add
"--disable-pdfium" to #:configure-flags.
* gnu/packages/xml.scm (xmlsec-nss): New public variable.