Remove gnutls and dependencies

This remvoes curl, libgsasl, libtasn1 and gnutls

• patches/gnutls-2.12.23/01-openssl-wincrypt.patch, patches/gnutls-2.12.23/02-cve-2013-2116.patch, patches/gnutls-2.12.23/03-cve-2014-1959.patch, patches/gnutls-2.12.23/04-cve-2014-0092.patch, patches/gnutls-2.12.23/05-cve-2014-3466.patch, patches/gnutls-2.12.23/06-cve-2015-0282.patch, patches/gnutls-2.12.23/07-cve-2015-0294.patch, patches/gnutls-2.12.23/25_updatedgdocfrommaster.patch, patches/gnutls-2.12.23/fix-gcrypt-private-api-usage.patch, patches/gnutls-2.12.23/gnulib-mingw-w64-fix.patch, patches/libtasn1-2.14/gnulib-mingw-w64-fix.patch, src/inst-curl.nsi, src/inst-gnutls.nsi, src/inst-libgsasl.nsi, src/inst-libtasn1.nsi, src/uninst-curl.nsi, src/uninst-gnutls.nsi, src/uninst-libgsasl.nsi, src/uninst-libtasn1.nsi: Removed.
• Makefile.am, configure.ac, packages/packages.current, src/Makefile.am, src/config.nsi.in, src/inst-sections.nsi: Update accordingly.