Fix some places where encoding issues manifest on ruby 2.0

Library/Homebrew/cmd/bottle.rb

@@ -67,7 +67,7 @@ module Homebrew extend self
       end
 
       # Use strings to search through the file for each string
-      IO.popen("strings -t x - '#{file}'") do |io|
+      IO.popen("strings -t x - '#{file}'", "rb") do |io|
         until io.eof?
           str = io.readline.chomp
 

Library/Homebrew/download_strategy.rb

@@ -144,7 +144,7 @@ class CurlDownloadStrategy < AbstractDownloadStrategy
   def buffered_write(tool)
     target = File.basename(basename_without_params, tarball_path.extname)
 
-    IO.popen("#{tool} -f '#{tarball_path}' -c") do |pipe|
+    IO.popen("#{tool} -f '#{tarball_path}' -c", "rb") do |pipe|
       File.open(target, "wb") do |f|
         buf = ""
         f.write(buf) while pipe.read(1024, buf)

Library/Homebrew/keg_fix_install_names.rb

@@ -86,7 +86,7 @@ class Keg < Pathname
   end
 
   def each_unique_file_matching string
-    IO.popen("/usr/bin/fgrep -lr '#{string}' '#{self}' 2>/dev/null") do |io|
+    IO.popen("/usr/bin/fgrep -lr '#{string}' '#{self}' 2>/dev/null", "rb") do |io|
       hardlinks = Set.new
 
       until io.eof?