For Capybara's own test suite, keep default_wait_time always at 1

Until now, we had it set at 0 for all tests that did't require `:js`.
But that would cause flickering failures when tests that didn't require
`:js` ran against Selenium, e.g. like this:

    visit '/foo' # asynchronous in Selenium
    page.should have_content 'Foo' # can fail if visit didn't finish in time

This change doubles(!) test suite run time, presumably because we are
testing for expected failures in a lot of places, causing us to retry
for the full default_wait_time period. At this point though I'm not sure
if there's a simple way to avoid the performance hit.

lib/capybara/spec/spec_helper.rb

@@ -12,15 +12,6 @@ module Capybara
           end
         end
         config.filter_run_excluding :requires => filter
-        config.around do |block|
-          if example.metadata[:requires] and example.metadata[:requires].include?(:js)
-            Capybara.default_wait_time = 1
-            block.run
-            Capybara.default_wait_time = 0
-          else
-            block.run
-          end
-        end
       end
 
       def spec(name, options={}, &block)

spec/dsl_spec.rb

@@ -110,13 +110,21 @@ describe Capybara::DSL do
   end
 
   describe '#using_wait_time' do
+    before do
+      @previous_wait_time = Capybara.default_wait_time
+    end
+
+    after do
+      Capybara.default_wait_time = @previous_wait_time
+    end
+
     it "should switch the wait time and switch it back" do
       in_block = nil
       Capybara.using_wait_time 6 do
         in_block = Capybara.default_wait_time
       end
       in_block.should == 6
-      Capybara.default_wait_time.should == 0
+      Capybara.default_wait_time.should == @previous_wait_time
     end
 
     it "should ensure wait time is reset" do
@@ -125,11 +133,7 @@ describe Capybara::DSL do
           raise "hell"
         end
       end.to raise_error
-      Capybara.default_wait_time.should == 0
-    end
-
-    after do
-      Capybara.default_wait_time = 0
+      Capybara.default_wait_time.should == @previous_wait_time
     end
   end
 

spec/spec_helper.rb

@@ -38,7 +38,7 @@ require 'capybara/spec/session'
 alias :running :lambda
 
 Capybara.app = TestApp
-Capybara.default_wait_time = 0 # less timeout so tests run faster
+Capybara.default_wait_time = 1 # less timeout so tests run faster
 
 module TestSessions
   RackTest = Capybara::Session.new(:rack_test, TestApp)