Remove unused file

pkgs/build-support/checker/default.nix

@@ -1,31 +0,0 @@
-#
-#  Checks that all set options are described.
-#
-options: configuration:
-with builtins;
-let lib=(import ../../lib); in
-with lib;
-
-let 
-  findInList = p: list: default:
-       if list == [] then default else
-       if (p (head list)) then (head list) else
-       findInList p (tail list) default;
-  
-
-  checkAttrInclusion = s: a: b:
-	(
-	if ! isAttrs b then s else
-	if (lib.attrByPath ["_type"] "" b) == "option" then "" else
-	findInList (x : x != "") 
-		( map (x: if (x == "servicesProposal") # this attr will be checked at another place ( -> upstart-jobs/default.nix )
-                       then ""
-                       else checkAttrInclusion 
-			(s + "." + x) 
-			(builtins.getAttr x a)
-			(lib.attrByPath [x] null b)) 
-		(attrNames a)) ""
-	);
-in 	
-	checkAttrInclusion "" configuration options
-