don't use pager on windows

Windows doesn't support `fork`.

Closes #97

lib/hub/commands.rb

@@ -742,7 +742,7 @@ help
 
     # http://nex-3.com/posts/73-git-style-automatic-paging-in-ruby
     def page_stdout
-      return unless $stdout.tty?
+      return if not $stdout.tty? or windows?
 
       read, write = IO.pipe
 

lib/hub/context.rb

@@ -294,16 +294,25 @@ module Hub
     # 
     # Returns an array, e.g.: ['open']
     def browser_launcher
-      require 'rbconfig'
-      browser = ENV['BROWSER'] ||
-        (RbConfig::CONFIG['host_os'].include?('darwin') && 'open') ||
-        (RbConfig::CONFIG['host_os'] =~ /msdos|mswin|djgpp|mingw|windows/ && 'start') ||
+      browser = ENV['BROWSER'] || (
+        osx? ? 'open' : windows? ? 'start' :
         %w[xdg-open cygstart x-www-browser firefox opera mozilla netscape].find { |comm| which comm }
+      )
 
       abort "Please set $BROWSER to a web launcher to use this command." unless browser
       Array(browser)
     end
 
+    def osx?
+      require 'rbconfig'
+      RbConfig::CONFIG['host_os'].to_s.include?('darwin')
+    end
+
+    def windows?
+      require 'rbconfig'
+      RbConfig::CONFIG['host_os'] =~ /msdos|mswin|djgpp|mingw|windows/
+    end
+
     # Cross-platform way of finding an executable in the $PATH.
     #
     #   which('ruby') #=> /usr/bin/ruby