Rename "use-substitutes" to "substitute"

Commit c2154d4c84 renamed
"build-use-substitutes" to "use-substitutes", but that broke
"nix-copy-closure --use-substitutes".

doc/manual/command-ref/conf-file.xml

@@ -312,7 +312,7 @@ false</literal>.</para>
   </varlistentry>
 
 
-  <varlistentry><term><literal>use-substitutes</literal></term>
+  <varlistentry><term><literal>substitute</literal></term>
 
     <listitem><para>If set to <literal>true</literal> (default), Nix
     will use binary substitutes if available.  This option can be

src/libstore/globals.hh

@@ -150,7 +150,7 @@ public:
     Setting<bool> syncBeforeRegistering{this, false, "sync-before-registering",
         "Whether to call sync() before registering a path as valid."};
 
-    Setting<bool> useSubstitutes{this, true, "use-substitutes",
+    Setting<bool> useSubstitutes{this, true, "substitute",
         "Whether to use substitutes.",
         {"build-use-substitutes"}};
 

tests/shell.shebang.sh

@@ -1,4 +1,4 @@
 #! @ENV_PROG@ nix-shell
-#! nix-shell -I nixpkgs=shell.nix --no-use-substitutes
+#! nix-shell -I nixpkgs=shell.nix --no-substitute
 #! nix-shell --pure -i bash -p foo bar
 echo "$(foo) $(bar) $@"