if the plugin is already installed, accept it as is.

This is useful for testing variants that have some plugins pre-installed.
added code to download path-element.hpi
refactored the controller so that Tomcat/JBoss/Winstone shares the same basic stuff
added a step to launch pry
newer version supports dynamic installation
transcoded one old test into a new format
no more legacy selenium test format
let's be bit more terse
Preliminal integration of Sauce OnDemand
Ugly workaround to make the checkbox click on Sauce OnDemand.

See
https://groups.google.com/d/topic/jenkinsci-dev/ttNFTt5Sm4Q/discussion
Capybara 2.0 compatibility not verified yet.

The error I get is this:

undefined method `body' for class `Sauce::Capybara::Driver' (NameError)
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/sauce-2.1.0/lib/sauce/capybara.rb:57:in `<class:Driver>'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/sauce-2.1.0/lib/sauce/capybara.rb:23:in `<module:Capybara>'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/sauce-2.1.0/lib/sauce/capybara.rb:11:in `<module:Sauce>'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/sauce-2.1.0/lib/sauce/capybara.rb:10:in `<top (required)>'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/sauce-cucumber-2.1.1/lib/sauce/cucumber.rb:4:in `require'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/sauce-cucumber-2.1.1/lib/sauce/cucumber.rb:4:in `<top (required)>'
/home/jenkins/slave/workspace/selenium-tests/features/support/env.rb:7:in `require'
/home/jenkins/slave/workspace/selenium-tests/features/support/env.rb:7:in `<top (required)>'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/rb_support/rb_language.rb:129:in `load'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/rb_support/rb_language.rb:129:in `load_code_file'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/runtime/support_code.rb:171:in `load_file'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/runtime/support_code.rb:83:in `block in load_files!'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/runtime/support_code.rb:82:in `each'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/runtime/support_code.rb:82:in `load_files!'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/runtime.rb:175:in `load_step_definitions'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/runtime.rb:40:in `run!'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/cli/main.rb:43:in `execute!'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/lib/cucumber/cli/main.rb:20:in `execute'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/gems/cucumber-1.2.1/bin/cucumber:14:in `<top (required)>'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/bin/cucumber:19:in `load'
/home/jenkins/.rvm/gems/ruby-1.9.3-p0@selenium-tests/bin/cucumber:19:in `<main>'
rake aborted!
Oops, this was a debug statement.
wrong file to require
added the first cut of the remote controller.

This work-in-progress controller uses vagrant to run Ubuntu in a virtual machine, then deploy Jenkins as a debian package in it.