Proxy prefetch cache becomes a command-line argument.

tests/acceptance/test_prefetch_proxy_mode.rb

@@ -0,0 +1,22 @@
+require 'test/unit'
+require 'environment'
+require 'proxy_tests'
+
+
+class TestPrefetchProxyMode < Test::Unit::TestCase
+  include ProxyTests
+
+  def setup
+    super
+    @env = Environment.new
+    @env.prefetch_proxy!
+    @env.writefile1( "f" * 16 )
+  end
+
+  def teardown
+    @env.cleanup
+    super
+  end
+end
+
+