update broken PKG_UPDATE rules, handle missing update rules * Makefile.in: add handling for packages with no update rule * src/gtk2.mk, src/gtk3.mk, src/libvpx.mk, src/taglib.mk, src/hunspell.mk, src/vala.mk : use github tags for version info * src/llvm.mk: add '?' to update url * src/openscenegraph.mk: update SED rule for version extraction * src/pthread-stubs.mk, src/qt5.mk, src/renderproto.mk, src/sm.mk, src/s2tc.mk, src/util-macros.mk: added dummy PKG_UPDATE rule * src/qscintilla.mk: change search name for version extraction * src/qtbase.mk: use short pkg version in update path * src/suitesparse.mk: update change in main url/version url * src/tre.mk: update download page link * src/vmime.mk: update download and update url * src/wget.mk, src/xapian-core.mk: update url, sed rule * src/wt.mk: update to use github download/update * src/src-msys-libcrypt.mk: update sed rule

Patch based on https://git.savannah.gnu.org/cgit/automake.git/commit/?id=13f00eb4493c217269b76614759e452d8302955e

diff -ur automake-1.11.6.orig/automake.in automake-1.11.6/automake.in
--- automake-1.11.6.orig/automake.in	2017-07-28 12:50:12.519289500 -0400
+++ automake-1.11.6/automake.in	2017-07-28 12:56:27.565672500 -0400
@@ -4156,7 +4156,7 @@
 sub substitute_ac_subst_variables ($)
 {
   my ($text) = @_;
-  $text =~ s/\${([^ \t=:+{}]+)}/&substitute_ac_subst_variables_worker ($1)/ge;
+  $text =~ s/\$[{]([^ \t=:+{}]+)}/&substitute_ac_subst_variables_worker ($1)/ge;
   return $text;
 }