build: add support for generic source sub-directories in modules

cmake/Templates.cmake

@@ -1,12 +1,18 @@
 function(add_bluelib_module)
 	set(options)
 	set(one_value_args NAME)
-	set(multi_value_args DEPENDENCIES)
+	set(multi_value_args DEPENDENCIES SUBDIRS)
 	cmake_parse_arguments(PARSE_ARGV 0 arg "${options}" "${one_value_args}" "${multi_value_args}")
 
 	set(module_name ${arg_NAME})
 
 	file(GLOB sources *.c *.h)
+
+	foreach (dir ${arg_SUBDIRS})
+		file(GLOB dir_sources ${dir}/*.c ${dir}/*.h)
+		set(sources ${sources} ${dir_sources})
+	endforeach (dir)
+
 	file(GLOB sys_sources sys/${b_system_name}/*.c sys/${b_system_name}/*.h)
 	set(root_header include/blue/${module_name}.h)
 	file(GLOB headers include/blue/${module_name}/*.h)