libowfat: update to version 0.31

now requires host-build to provide the 'ent' build-tool which generates
entities.h for use in scan_html.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

libs/libowfat/patches/001-fixbuild.patch

@@ -1,6 +1,6 @@
 --- a/GNUmakefile
 +++ b/GNUmakefile
-@@ -278,6 +278,8 @@ socket_accept4.o socket_accept6.o socket
+@@ -343,6 +343,8 @@ socket_accept4.o socket_accept6.o socket
  socket_local6.o socket_recv4.o socket_recv6.o socket_remote4.o \
  socket_remote6.o: havesl.h
  
@@ -9,3 +9,11 @@
  dns_nd6.o fmt_xlong.o scan_xlong.o fmt_ip6_flat.o $(TEXTCODE_OBJS): haveinline.h
  
  iob_send.o scan_ip6if.o: havealloca.h
+@@ -372,6 +374,6 @@ update:
+ 	dl -n http://www.w3.org/TR/html5/entities.json
+ 
+ entities.h: entities.json ent
+-	./ent
++	libowfat-ent
+ 
+ scan_html.o: entities.h