Issue #6157: Fixed Tkinter.Text.debug().  Original patch by Guilherme Polo.
Issue #19085: Fixed pixels rounding for last Tk patchlevels.
Issue #18702: All skipped tests now reported as skipped.
Fix test_os (issue #18702).
Issue #19391: Clean up PCbuild/readme.txt
Issue #15392: Install idlelib/idle_test.
Issue #17883: Backport test.test_support._is_gui_available()

This should stop the Windows buildbots from hanging on test_ttk_guionly.
Issue #XXXXX: Fix test_idle so that idlelib test cases are actually run
under test.regrtest on 2.7.
Issue #17883: Tweak test_tcl testLoadWithUNC to skip the test in the
event of a permission error on Windows and to properly report other
skip conditions.