libsigc++ 2.4.0

Update to latest stable release, remove unnecessary patch, change
formatting of make commands, change single quotes to double.

Closes Homebrew/homebrew#32505.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/libsigc++.rb

@@ -1,9 +1,9 @@
-require 'formula'
+require "formula"
 
 class Libsigcxx < Formula
-  homepage 'http://libsigc.sourceforge.net'
-  url 'http://ftp.gnome.org/pub/GNOME/sources/libsigc++/2.2/libsigc++-2.2.11.tar.xz'
-  sha256 '9834045f74f56752c2c6b3cdc195c30ab8314ad22dc8e626d6f67f940f1e4957'
+  homepage "http://libsigc.sourceforge.net"
+  url "http://ftp.gnome.org/pub/GNOME/sources/libsigc++/2.4/libsigc++-2.4.0.tar.xz"
+  sha256 "7593d5fa9187bbad7c6868dce375ce3079a805f3f1e74236143bceb15a37cd30"
 
   bottle do
     sha1 "c3c2dd772631225eba25b4df6ce357a41f88af11" => :mavericks
@@ -13,28 +13,11 @@ class Libsigcxx < Formula
 
   option :cxx11
 
-  # apply this patch for C++11 mode
-  # see https://git.gnome.org/browse/libsigc++2/commit/tests/test_cpp11_lambda.cc?id=cd600a31fbf8e76e25f4be4c10c0645f090a9b80
-  patch :DATA if build.cxx11?
-
   def install
     ENV.cxx11 if build.cxx11?
     system "./configure", "--prefix=#{prefix}", "--disable-dependency-tracking"
     system "make"
-    system "make check"
-    system "make install"
+    system "make", "check"
+    system "make", "install"
   end
 end
-__END__
-diff -u a/tests/test_cpp11_lambda.cc b/tests/test_cpp11_lambda.cc
---- a/tests/test_cpp11_lambda.cc
-+++ b/tests/test_cpp11_lambda.cc
-@@ -312,7 +312,7 @@
-
-   //std::cout << (sigc::group(sigc::mem_fun(&bar::test), _1, _2, _3)) (sigc::ref(the_bar), 1, 2) << std::endl;
-   result_stream << std::bind(std::mem_fn(&bar::test), std::placeholders::_1,
--    std::placeholders::_2, std::placeholders::_3)(std::ref(the_bar), 1, 2);
-+    std::placeholders::_2, std::placeholders::_3)(the_bar, 1, 2);
-   check_result("bar::test(int 1, int 2)6");
-
-   // same functionality as bind