Added contrib plugin link on doc page.
Merge pull request #1093 from untergeek/docfix-untergeek

Docfix untergeek
Fixed some issues in the tutorial

* Fixed a code formatting issue
* Consistently capitalized Logstash
Merge pull request #1095 from jamtur01/docfixes

Fixed some issues in the tutorial
Remove extra "mail" dependency in logstash.gemspec
Add rescue blocak to bundle install loop in gembag.rb
Merge pull request #1096 from mrsolo/gemfixes

Install cleanups
Add Multi-threaded workers and queues to UDP input
Added config item for queue_size