liblo is required; update dpf submodule

Makefile.mk

@@ -72,6 +72,10 @@ $(error X11 missing, cannot continue)
 endif
 endif
 
+ifneq ($(shell pkg-config --exists liblo && echo true),true)
+$(error liblo missing, cannot continue)
+endif
+
 # --------------------------------------------------------------
 # Set libs stuff
 

dpf

@@ -1 +1 @@
-Subproject commit 642b7866dd97429bfa2c2ddb1da57c4902fc40eb
+Subproject commit 8fd0d9072b164d9d83f7e34c420131aeafdc315a