Mark failing specs as pending on windows and ruby 2 x64

Some tests were failing on windows and ruby 2 x64 due to the task scheduler provider not yet working (PUP-2881) and the eventlog gem used in x64 introducing backwards incompatible changes (PUP-2889). Those tests have been marked as conditionally pending when running on Windows and Ruby 2.

Also we are running ruby 2 specs on win2012r2, and Windows changed the system error message. The tests have been updated to rely on the Win32 error code instead of the error message.