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
Prevent an exception with large num_retries.

If the calculated wait time is infinite, don't try to do
further calculations on it to prevent it from becoming NaN.
This could happen if num_retries becomes too large (>1024).
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
Refactor in_monitor_agent to remove unnecessary instance eval
reorder conditional to handle NaN or Infinite
Merge pull request #502 from mr-salty/fix-max-retry-exception

Prevent an exception with large num_retries.
Accept '@type' and '@id' in v1 configuration. fixes #500

Plugin type and id are system reserved parameters like @label.
So using '@' prefix is better for separating normal plugin parameters.
in_monitor_agent supports '@type' and '@id' query
Merge pull request #503 from fluent/at-prefix-for-type-and-id-parameters

Accept '@type' and '@id' in v1 configuration. fixes #500
Fix tag parameter handling in in_monitor_agent
Fix blank handling of TSVParser. fixes #505
Merge pull request #506 from fluent/fix-tsv-parser

Fix blank handling of TSVParser. fixes #505