Refactor WindowsFileDelegate and tests to finish WindowsFileDelegateTest.

This change refactors WindowsFileDelegate, WindowsFileDelegateTest,
and WindowsAclFileAttributeViewsTest to enable testing of the rest of
WindowsFileDelegate.  The refactoring does the following:

- Allows for injection of the Windows JNA and WindowsAclFileAttributeViews
  implementations into WindowsFileDelegate.

- Extracts Ace, AceBuilder, AccountSid, Serialized DACL construction,
  temp file management, and TestWindowsAclFileAttributeViews into a base
  class, TestWindowsAclViews, that can be extended by both
  WindowsAclFileAttributeViewsTest and WindowsFileDelegateTest.

This CL is a strict refactoring, and adds no new functionality or tests.

Code Review: http://codereview.appspot.com/88090047
4 files changed