Reviewed by Eric Seidel.

        Remove steps_references and commands_references
        https://bugs.webkit.org/show_bug.cgi?id=37758

        We tried using the mumble_references convention to manage our
        dependencies, but it doesn't seem to be providing much value for the
        steps and commands module because these modules are small pieces of the
        larger tool module.  In this patch, I've removed the references file
        for these modules.

        I've left the style_references file for the style module because that
        module seems better isolated from the rest of webkitpy and the
        style_references file appears to be providing some value.

        * Scripts/webkitpy/tool/commands/commandtest.py:
        * Scripts/webkitpy/tool/commands/download_unittest.py:
        * Scripts/webkitpy/tool/commands/earlywarningsystem_unittest.py:
        * Scripts/webkitpy/tool/commands/queries_unittest.py:
        * Scripts/webkitpy/tool/commands/queues_unittest.py:
        * Scripts/webkitpy/tool/commands/queuestest.py:
        * Scripts/webkitpy/tool/commands/upload.py:
        * Scripts/webkitpy/tool/commands/upload_unittest.py:
        * Scripts/webkitpy/tool/commands_references.py: Removed.
        * Scripts/webkitpy/tool/steps/closebugforlanddiff_unittest.py:
        * Scripts/webkitpy/tool/steps/steps_unittest.py:
        * Scripts/webkitpy/tool/steps/updatechangelogswithreview_unittest.py:
        * Scripts/webkitpy/tool/steps/validatereviewer_unittest.py:
        * Scripts/webkitpy/tool/steps_references.py: Removed.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@57788 268f45cc-cd09-0410-ab3c-d52691b4dbfc