Improved plugins Makefile

- It is now possible to build a plugin without adding it to the
  Makefile, by using 'make plugin.my_plugin_name'.
- To have it built through 'make all' or 'make plugins', it is still
  necessary to add it to the Makefile, as before.

Signed-off-by: Haru <haru@dotalux.com>

src/plugins/Makefile.in

@@ -6,13 +6,22 @@
 #                                                                    #
 # MYPLUGINS = my_cool_plugin my_second_plugin                        #
 #                                                                    #
+# This is only needed if you want to build your plugin through       #
+#   'make plugins' or 'make all'. If you don't add it to this list,  #
+#   you will still be able to build your plugin through              #
+#   'make plugin.my_plugin'                                          #
+#                                                                    #
 # Note: DO NOT include the .c extension!!!                           #
 
 MYPLUGINS = 
 
 #                                                                    #
 #########  DO NOT EDIT ANYTHING BELOW THIS LINE!!!  ##################
 
+# All plugins in the src/plugins directory
+ALLPLUGINS = $(basename $(wildcard *.c))
+
+# Plugins that will be built through 'make plugins' or 'make all'
 PLUGINS = sample db2sql HPMHooking $(MYPLUGINS)
 
 COMMON_D = ../common
@@ -32,11 +41,11 @@ CC = @CC@
 export CC
 
 #####################################################################
-.PHONY: all $(PLUGINS) clean buildclean help
+.PHONY: all $(ALLPLUGINS) clean buildclean help
 
 all: $(PLUGINS) Makefile
 
-$(PLUGINS): %: ../../plugins/%@DLLEXT@
+$(ALLPLUGINS): %: ../../plugins/%@DLLEXT@
 
 buildclean:
 	@echo "	CLEAN	plugins (build temp files)"