use Array.join instead of Array.inject, add .svn to defaults

lib/jekyll.rb

@@ -59,7 +59,7 @@ module Jekyll
     'source'       => Dir.pwd,
     'destination'  => File.join(Dir.pwd, '_site'),
     'plugins'      => File.join(Dir.pwd, '_plugins'),
-    'keep_files'   => ['.git'],
+    'keep_files'   => ['.git','.svn'],
     'layouts'      => '_layouts',
 
     'future'       => true,

lib/jekyll/site.rb

@@ -251,7 +251,7 @@ module Jekyll
     # create a regex from the keep_files array
     # ['.git','.svn'] => /\/(\.git|\/.svn)/
     def keep_file_regex
-      or_list = self.keep_files.map.inject("") { |x,y| "#{x}|#{y}" }[1..-1]
+      or_list = self.keep_files.join("|")
       pattern = "\/(#{or_list.gsub(".", "\.")})"
       Regexp.new pattern
     end