Update packages

• packages/packages.current (gettext): Updated to 0.19.1 (curl): Updated to 7.37.0 (libxml2): Updated to 2.9.1 (glib): Updated to 2.41 (gdk-pixbuf): Updated to 2.30.8 (gtk+): Updated to 2.24.24 (libpng): Updated to 1.4.13 (libgpg-error): Updated to 1.13 (gnupg): Updated to 2.0.25 (gpgme): Updated to 1.5.0 (adns): Updated to 1.4-g10-4 (qt): Updated to 4.8.6 (kleopatra): Updated to KDE 4.13 (git95c52d)
• src/Makefile.am (gpg4win_pkg_libpng_configure): Add workaround for a configure error introduced by 1.4.13