Only use the first line of the cuke feature name in the cassette name.

Closes vcr#157.

features/test_frameworks/cucumber.feature

@@ -75,6 +75,10 @@ Feature: Usage with Cucumber
       """
       Feature: VCR example
 
+        Note: Cucumber treats the pre-amble as part of the feature name. When
+        using the :use_scenario_name option, VCR will only use the first line
+        of the feature name as the directory for the cassette.
+
         @localhost_request
         Scenario: tagged scenario
           When a request is made to "http://localhost:7777/localhost_request_1"

lib/vcr/test_frameworks/cucumber.rb

@@ -38,7 +38,7 @@ def tags(*tag_names)
           options = original_options.dup
 
           cassette_name = if options.delete(:use_scenario_name)
-            "#{scenario.feature.name}/#{scenario.name}"
+            "#{scenario.feature.name.split("\n").first}/#{scenario.name}"
           else
             "cucumber_tags/#{tag_name.gsub(/\A@/, '')}"
           end

spec/vcr/test_frameworks/cucumber_spec.rb

@@ -6,7 +6,7 @@
   let(:after_blocks_for_tags) { {} }
 
   def scenario(name)
-    stub(:name => name, :feature => stub(:name => "My feature name"))
+    stub(:name => name, :feature => stub(:name => "My feature name\nThe preamble text is not included"))
   end
 
   let(:current_scenario) { scenario "My scenario name" }