Merge pull request #74 from dje4g/add-newline-2

Add blank line after build rules, for human readability.
diff --git a/build.ninja.in b/build.ninja.in
index 9b2d0c9..9ba88c8 100644
--- a/build.ninja.in
+++ b/build.ninja.in
@@ -206,6 +206,7 @@
         ${g.bootstrap.buildDir}/.bootstrap/choosestage/obj/choosestage.a | $
         ${g.bootstrap.linkCmd}
 default ${g.bootstrap.buildDir}/.bootstrap/choosestage/obj/a.out
+
 build ${g.bootstrap.BinDir}/choosestage: g.bootstrap.cp $
         ${g.bootstrap.buildDir}/.bootstrap/choosestage/obj/a.out
 default ${g.bootstrap.BinDir}/choosestage
@@ -228,6 +229,7 @@
         ${g.bootstrap.buildDir}/.bootstrap/gotestmain/obj/gotestmain.a | $
         ${g.bootstrap.linkCmd}
 default ${g.bootstrap.buildDir}/.bootstrap/gotestmain/obj/a.out
+
 build ${g.bootstrap.BinDir}/gotestmain: g.bootstrap.cp $
         ${g.bootstrap.buildDir}/.bootstrap/gotestmain/obj/a.out
 default ${g.bootstrap.BinDir}/gotestmain
@@ -250,6 +252,7 @@
         ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/gotestrunner.a | $
         ${g.bootstrap.linkCmd}
 default ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/a.out
+
 build ${g.bootstrap.BinDir}/gotestrunner: g.bootstrap.cp $
         ${g.bootstrap.buildDir}/.bootstrap/gotestrunner/obj/a.out
 default ${g.bootstrap.BinDir}/gotestrunner
@@ -316,8 +319,10 @@
         s.bootstrap.minibp ${g.bootstrap.srcDir}/Blueprints | $
         ${g.bootstrap.bootstrapManifest} ${g.bootstrap.BinDir}/minibp
 default ${g.bootstrap.buildDir}/.bootstrap/bootstrap.ninja.in
+
 build ${g.bootstrap.buildDir}/.bootstrap/notAFile: phony
 default ${g.bootstrap.buildDir}/.bootstrap/notAFile
+
 build ${g.bootstrap.buildDir}/.bootstrap/build.ninja.in: $
         g.bootstrap.chooseStage $
         ${g.bootstrap.buildDir}/.bootstrap/bootstrap.ninja.in $
diff --git a/ninja_defs.go b/ninja_defs.go
index 0919ea4..a49d309 100644
--- a/ninja_defs.go
+++ b/ninja_defs.go
@@ -354,7 +354,7 @@
 		nw.Default(outputs...)
 	}
 
-	return nil
+	return nw.BlankLine()
 }
 
 func valueList(list []*ninjaString, pkgNames map[*PackageContext]string,