fix picat out-of-src, document svg11-relaxng install

Makefile.am

@@ -80,6 +80,9 @@ unknown:
 	if test -s examples/alldwg.skip; then true; \
 	else mv examples/alldwg.skip~ examples/alldwg.skip; fi
 if HAVE_PICAT
+if !HAVE_INSRCDIR
+	ln -s $(srcdir)/unknown.pi unknown.pi
+endif
 if HAVE_PARALLEL
 	-rm examples/*.pi.tmplog 2>/dev/null
 	echo $(PARALLEL) $(TIMEOUT_30) $(PICAT) "{} \\>{}.tmplog ::: examples/[A-Z]*.pi"

README

@@ -64,6 +64,9 @@ Optionally:
   LaTeXML used to have a broken svg11-basic.rng. If so
   the zip from http://yupotan.sppd.ne.jp/relax-ng/svg11/ is correct.
   Needs to be installed into /usr/local/share/relaxng/svg11/
+  sudo unzip ~/Downloads/svg11-relaxng-20060604.zip -d  /usr/local/share/relaxng/
+  On Ubuntu I needed:
+  apt install jing libjaxp1.3-java libbatik-java libavalon-framework-java
 - mapbox/geojsonhint as geojson linter
   npm install -g @mapbox/geojsonhint
 - geojson-validation as 2nd geojson fallback linter