Added support to queue file for nested includes.

Change-Id: Ia22eb951218efac8b3f54f41bcd8130d0d12d42b
diff --git a/aos/build/queues/output/q_file.rb b/aos/build/queues/output/q_file.rb
index 471bdcb..a2f438d 100644
--- a/aos/build/queues/output/q_file.rb
+++ b/aos/build/queues/output/q_file.rb
@@ -49,7 +49,11 @@
 	def initialize(path)
 		@path = path
 	end
+	def extern=(value)
+		@extern=value
+	end
 	def create(cpp_tree)
+		return if (@extern)
 #		inc = cpp_tree.header.add_include("\"#{@path}\"")
 		inc = cpp_tree.add_header_include("\"#{@path}\"")
 		cpp_tree.set(self,inc)