dpkg: upgrade to 1.17.1 and fix perl scripts

- Upgrade dpkg to 1.17.1 (most recent release, in debian unstable)

 - Disable dselect and update-alternatives, as they won't work as
   intended in homebrew.

 - Install dpkg Perl modules to $(prefix)/perl, and adjust the shebang
   on Perl scripts to point there using an existing do_perl_subst fn.

Closes Homebrew/homebrew#21742.

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

Formula/dpkg.rb

@@ -1,11 +1,12 @@
 require 'formula'
 
 class Dpkg < Formula
-  homepage 'http://en.wikipedia.org/wiki/Dpkg'
-  url 'http://ftp.debian.org/debian/pool/main/d/dpkg/dpkg_1.15.8.13.tar.bz2'
-  sha1 'd0b9386742f966345a23c3daa0391b37fa837a3f'
+  homepage 'https://wiki.debian.org/Teams/Dpkg'
+  url 'http://ftp.debian.org/debian/pool/main/d/dpkg/dpkg_1.17.1.tar.xz'
+  sha1 'c94b33573806cf9662c5a6f2bbae64900113a538'
 
   depends_on 'pkg-config' => :build
+  depends_on 'xz' => :build
   depends_on 'gnu-tar'
 
   fails_with :clang do
@@ -19,10 +20,10 @@ class Dpkg < Formula
   def install
     system "./configure", "--disable-dependency-tracking",
                           "--prefix=#{prefix}",
-                          "--disable-compiler-warnings",
+                          "--disable-dselect",
                           "--disable-linker-optimisations",
-                          "--disable-compiler-optimisations",
-                          "--without-start-stop-daemon"
+                          "--disable-start-stop-daemon",
+                          "--disable-update-alternatives"
     system "make"
     system "make install"
   end
@@ -36,32 +37,56 @@ end
 
 __END__
 diff --git a/configure b/configure
-index a4e8516..de7f226 100755
+index 5d91530..dd2ca11 100755
 --- a/configure
 +++ b/configure
-@@ -8180,9 +8180,9 @@ else
- $as_echo "no" >&6; }
+@@ -8388,9 +8388,7 @@ if test "$PERL" = "no" || test ! -x "$PERL"; then
  fi
- 
+ # Let the user override the variable.
+ if test -z "$PERL_LIBDIR"; then
 -PERL_LIBDIR=$($PERL -MConfig -e 'my $r = $Config{vendorlibexp};
 -                                 $r =~ s/$Config{vendorprefixexp}/\$(prefix)/;
 -                                 print $r')
-+PERL_LIBDIR=$($PERL -MConfig -e 'my $r = $Config{sitelib}; 
-+                                 $r =~ s/$Config{sitelib}/\$(prefix)/;
-+                                 print $r')
++PERL_LIBDIR="$prefix/perl"
+ fi
+ 
  
- for ac_prog in pod2man
- do
 diff --git a/lib/dpkg/dpkg.h b/lib/dpkg/dpkg.h
-index ba6066c..89a66ba 100644
+index c0f633d..b692806 100644
 --- a/lib/dpkg/dpkg.h
 +++ b/lib/dpkg/dpkg.h
-@@ -97,7 +97,7 @@
- #define DPKG  	"dpkg"
+@@ -108,7 +108,7 @@ DPKG_BEGIN_DECLS
+ #define DPKG		"dpkg"
  #define DEBSIGVERIFY	"/usr/bin/debsig-verify"
  
 -#define TAR		"tar"
 +#define TAR		"gnutar"
  #define RM		"rm"
+ #define CAT		"cat"
  #define FIND		"find"
- #define DIFF		"diff"
+diff --git a/scripts/Makefile.am b/scripts/Makefile.am
+index f83adff..d2b5043 100644
+--- a/scripts/Makefile.am
++++ b/scripts/Makefile.am
+@@ -117,7 +117,7 @@ nobase_dist_perllib_DATA = \
+ man3_MANS =
+ 
+ do_perl_subst = $(AM_V_GEN) \
+-		sed -e "s:^\#![[:space:]]*/usr/bin/perl:\#!$(PERL):" \
++		sed -e "s:^\#![[:space:]]*/usr/bin/perl:\#!$(PERL) -I$(PERL_LIBDIR):" \
+ 		    -e "s:\$$CONFDIR[[:space:]]*=[[:space:]]*['\"][^'\"]*['\"]:\$$CONFDIR='$(pkgconfdir)':" \
+ 		    -e "s:\$$ADMINDIR[[:space:]]*=[[:space:]]*['\"][^'\"]*['\"]:\$$ADMINDIR='$(admindir)':" \
+ 		    -e "s:\$$LIBDIR[[:space:]]*=[[:space:]]*['\"][^'\"]*['\"]:\$$LIBDIR='$(pkglibdir)':" \
+diff --git a/scripts/Makefile.in b/scripts/Makefile.in
+index 754488e..8b233fb 100644
+--- a/scripts/Makefile.in
++++ b/scripts/Makefile.in
+@@ -486,7 +486,7 @@ nobase_dist_perllib_DATA = \
+ # Keep it even if empty to have man3dir correctly set
+ man3_MANS = 
+ do_perl_subst = $(AM_V_GEN) \
+-		sed -e "s:^\#![[:space:]]*/usr/bin/perl:\#!$(PERL):" \
++		sed -e "s:^\#![[:space:]]*/usr/bin/perl:\#!$(PERL) -I$(PERL_LIBDIR):" \
+ 		    -e "s:\$$CONFDIR[[:space:]]*=[[:space:]]*['\"][^'\"]*['\"]:\$$CONFDIR='$(pkgconfdir)':" \
+ 		    -e "s:\$$ADMINDIR[[:space:]]*=[[:space:]]*['\"][^'\"]*['\"]:\$$ADMINDIR='$(admindir)':" \
+ 		    -e "s:\$$LIBDIR[[:space:]]*=[[:space:]]*['\"][^'\"]*['\"]:\$$LIBDIR='$(pkglibdir)':" \