ctags: Avoid linking to libxml2

packages/ctags/configure.ac.patch

@@ -0,0 +1,16 @@
+diff -u -r ../ctags-c82fb5e615de043ef98926ef21fc3f8cb4a57ae7/configure.ac ./configure.ac
+--- ../ctags-c82fb5e615de043ef98926ef21fc3f8cb4a57ae7/configure.ac	2016-05-02 02:37:13.000000000 -0400
++++ ./configure.ac	2016-05-02 21:15:55.462438802 -0400
+@@ -586,11 +586,7 @@
+ 
+ AH_TEMPLATE([HAVE_LIBXML],
+ 	[Define this value if libxml is available.])
+-PKG_CHECK_MODULES(LIBXML, libxml-2.0,
+-		       [have_libxml=yes
+-		       AC_DEFINE(HAVE_LIBXML)],
+-		       [have_libxml=no])
+-AM_CONDITIONAL(HAVE_LIBXML, test "x$have_libxml" = xyes)
++AM_CONDITIONAL(HAVE_LIBXML, test "no" = xyes)
+ 
+ AC_CHECK_FUNCS(fmemopen,[have_fmemopen=yes],[have_fmemopen=no])
+ AM_CONDITIONAL(HAVE_FMEMOPEN, test "x$have_fmemopen" = xyes)