Add basic support for dynamically loadable plugins

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

common.mk

@@ -1,5 +1,6 @@
 # Some junk files we always want to be removed when doing a make clean.
 JUNK       = *~ *.bak *.aux *.dvi *.idx *.ind *.log *.ps *.map .*.d DEADJOE semantic.cache *.gdb *.elf core core.*
+RM        := -@$(RM)
 MAKE      := @$(MAKE)
 MAKEFLAGS  = --no-print-directory
 
@@ -17,3 +18,7 @@ MAKEFLAGS  = --no-print-directory
 %: %.o
 	@printf "  LINK    $(subst $(ROOTDIR)/,,$(shell pwd)/$@)\n"
 	@$(CC) $(CFLAGS) $(LDFLAGS) -Wl,-Map,$@.map -o $@ $^ $(LDLIBS$(LDLIBS-$(@)))
+
+%.so: %.o
+	@printf "  PLUGIN  $(subst $(ROOTDIR)/,,$(shell pwd)/$@)\n"
+	@$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS)