Update emacs to 25.1

Update emacs from 24.4 to 25.1. Change to src/alloc. no longer needed.

packages/emacs.rb

 require 'package'
 
 class Emacs < Package
-  version '24.4'
-  source_url 'ftp://ftp.gnu.org/gnu/emacs/emacs-24.4.tar.xz'
-  source_sha1 '68f9b1f7570a13d076b94c20f2d20fe40782031c'
+  version '25.1'
+  source_url 'ftp://ftp.gnu.org/gnu/emacs/emacs-25.1.tar.xz'
+  source_sha1 '983e457971e3e3c8964d039c113033f98132b8a8'
 
   depends_on "diffutils"
   depends_on "m4"
@@ -12,7 +12,6 @@ class Emacs < Package
 
   def self.build
     system "./configure --prefix=/usr/local --without-x --without-makeinfo --without-selinux"
-    system "sed -i '/static void \\*/{ N; /static void \\*\\naligned_alloc/{ s/static //g}}' src/alloc.c"
     system "make"
   end