Interfaceregistry for 'active' interfaces

All interfaces which are available get registered in a tree.
This will be used internal for lookup interfaces. The higher level calls
will be an	amalgamation of this lookup and the upcoming plugindb and
loader.

src/backend/Makefile.am

@@ -46,7 +46,7 @@ noinst_HEADERS +=						\
 	$(liblumibackend_a_srcdir)/filehandle.h			\
 	$(liblumibackend_a_srcdir)/filedescriptor.h		\
 	$(liblumibackend_a_srcdir)/filehandlecache.h		\
-	$(liblumibackend_a_srcdir)/interface.c			\
+	$(liblumibackend_a_srcdir)/interface.h			\
 	$(liblumibackend_a_srcdir)/interfaceregistry.h		\
 	$(liblumibackend_a_srcdir)/interfacedescriptor.h	\
 	$(liblumibackend_a_srcdir)/config.h 			\

src/backend/interfaceregistry.c

@@ -80,7 +80,6 @@ lumiera_interfacenode_delete (LumieraInterfacenode self)
 }
 
 
-
 /**
  * Initialize the interface registry
  */