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

--- a/src/pthread-stubs.mk	Wed Mar 07 06:44:54 2018 -0500
+++ b/src/pthread-stubs.mk	Fri Mar 09 11:46:42 2018 -0500
@@ -10,6 +10,11 @@
 $(PKG)_URL      := http://xcb.freedesktop.org/dist/$($(PKG)_FILE)
 $(PKG)_DEPS     := 
 
+define $(PKG)_UPDATE
+    echo 'Warning: Updates are temporarily disabled for package $(PKG).' >&2;
+    echo $($(PKG)_VERSION)
+endef
+
 ifeq ($(MXE_WINDOWS_BUILD),yes)
   define $(PKG)_BUILD
   endef