swc-installation-test-2.py: Use _ROOT_PATH for MS Windows compatability

I don't think starting a path with os.sep gives you a root path on
Windows.  We need the backslash in _ROOT_PATH, because:

  os.path.join('c:', 'foo')

gives 'c:foo', a path relative to the current directory on drive C: [1].

[1]: http://docs.python.org/3/library/os.path.html#os.path.join

setup/swc-installation-test-2.py

@@ -101,6 +101,10 @@ def import_module(name):
 
 CHECKER = {}
 
+_ROOT_PATH = _os.sep
+if _platform.system() == 'win32':
+    _ROOT_PATH = 'c:\\'
+
 
 class InvalidCheck (KeyError):
     def __init__(self, check):
@@ -578,16 +582,16 @@ def _get_version(self):
 
 
 for paths,name,long_name in [
-        ([_os.path.join(_os.sep, 'Applications', 'Sublime Text 2.app')],
+        ([_os.path.join(_ROOT_PATH, 'Applications', 'Sublime Text 2.app')],
          'sublime-text', 'Sublime Text'),
-        ([_os.path.join(_os.sep, 'Applications', 'TextMate.app')],
+        ([_os.path.join(_ROOT_PATH, 'Applications', 'TextMate.app')],
          'textmate', 'TextMate'),
-        ([_os.path.join(_os.sep, 'Applications', 'TextWrangler.app')],
+        ([_os.path.join(_ROOT_PATH, 'Applications', 'TextWrangler.app')],
          'textwrangler', 'TextWrangler'),
-        ([_os.path.join(_os.sep, 'Applications', 'Safari.app')],
+        ([_os.path.join(_ROOT_PATH, 'Applications', 'Safari.app')],
          'safari', 'Safari'),
-        ([_os.path.join(_os.sep, 'Applications', 'Xcode.app'),  # OS X >=1.7
-          _os.path.join(_os.sep, 'Developer', 'Applications', 'Xcode.app'
+        ([_os.path.join(_ROOT_PATH, 'Applications', 'Xcode.app'),  # OS X >=1.7
+          _os.path.join(_ROOT_PATH, 'Developer', 'Applications', 'Xcode.app'
                         )  # OS X 1.6,
           ],
          'xcode', 'Xcode'),