Define RUBY_ENGINE for padrino-core under 1.8.7 and 1.9.3
Define RUBY_ENGINE for padrino-core under 1.8.7 and 1.9.3

tlunter/oboe-ruby,tlunter/oboe-ruby,appneta/ruby-traceview,boyang-li/oboe-ruby,tlunter/oboe-ruby,boyang-li/oboe-ruby,tlunter/oboe-ruby,appneta/ruby-traceview,appneta/ruby-traceview,appneta/ruby-traceview,boyang-li/oboe-ruby,boyang-li/oboe-ruby