Added respond with empty image for Issue #86 based on work by @parolkar
Merge remote-tracking branch 'github/master'
Made the 1 pixel image a constant
Added tests for respond_with_empty_img
Fixed option type from string 'false' to false
Updated test after hitting an issue with [Net:HTTP encoding](https://bugs.ruby-lang.org/issues/2567), thanks to @kioto for the help with this
Fixed in_httpd test for Ruby 1.9.3 by forcing the encoding on EMPTY_GIF_IMAGE
Merge pull request #480 from Telmo/master

Add respond with empty image