handle multi bye characters in ruby 1.9.2
handle multi bye characters in ruby 1.9.2

  Ruby 1.9.2 does not support byteslice
  Ruby 1.8.7 does not support force_encoding

  forcing this code to branch for Ruby 1.9.2
  and convert the string to binary and then back to UTF-8
bblimke/webmock,hobodave/webmock,davidbegin/webmock,taiki45/webmock,hilben/webmock