Fixing the star on unit tests for Windows consoles

Summary: On Windows consoles, the star on the unit tests (I'm assuming it's a Unicode character of some kind), doesn't render correctly and you just get garbage.  This fixes it so that on Windows, it falls back to just using an ASCII asterisk.

Test Plan: On Windows run some unit tests, the star should now be a plain asterisk.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D6087
Use a temporary file to execute `arc patch`

Summary:
Piping data around on Windows doesn't work well when it contains zany characters like "null" and "newline". Fixes T3266.

Instead of piping data into `git apply`, write to a temporary file.

Test Plan:
Ran `arc patch`, got good results.

  >>> [17] <exec> $ git apply --index --reject -- '/private/var/folders/8k/c3vkmjy5335gcxdzxkhwq82w0000gn/T/7z9iea6srikoo0sc/4266-ZEyvz9'

Reviewers: btrahan, hach-que

Reviewed By: hach-que

CC: aran

Maniphest Tasks: T3266

Differential Revision: https://secure.phabricator.com/D6070
Merge branch 'master' of http://github.com/facebook/arcanist