Add basic support for dynamically loadable plugins

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

plugins/Makefile

@@ -0,0 +1,32 @@
+# Plugin based services architecture for finit -*-Makefile-*-
+CFLAGS      = -fPIC -g -Os -I..
+CPPFLAGS    = -W -Wall
+LDFLAGS     = -shared 
+PLUGINS     = foo.so
+DEPS        = $(addprefix .,$(PLUGINS:.so=.d))
+
+include ../common.mk
+
+all: $(PLUGINS)
+
+clean:
+	$(RM) $(PLUGINS) *.o
+
+distclean: clean
+	$(RM) $(JUNK) $(DEPS)
+
+install: all
+	@for plugin in $(PLUGINS); do \
+		echo "  INSTALL $(PLUGIN_DIR)/$$plugin"; \
+		cp $$plugin $(PLUGIN_DIR); \
+	done
+
+uninstall:
+	@for plugin in $(PLUGINS); do \
+		echo "  RM      $(PLUGIN_DIR)/$$plugin"; \
+		rm $(PLUGIN_DIR)/$$plugin; \
+	done
+
+ifneq ($(MAKECMDGOALS),clean)
+ -include $(DEPS)
+endif