Convert cpplint.py to work with nested git repositories.

cpplint.py

Index: cpplint.py
diff --git a/cpplint.py b/cpplint.py
index 27def382726681d2a1254b1c6782a669482332f7..4b067d473b32970301ea1ad158aed24e452bea06 100755
--- a/cpplint.py
+++ b/cpplint.py
@@ -1014,12 +1014,13 @@ class FileInfo(object):
 
       # Not SVN <= 1.6? Try to find a git, hg, or svn top level directory by
       # searching up from the current path.
-      root_dir = os.path.dirname(fullname)
-      while (root_dir != os.path.dirname(root_dir) and
-             not os.path.exists(os.path.join(root_dir, ".git")) and
-             not os.path.exists(os.path.join(root_dir, ".hg")) and
-             not os.path.exists(os.path.join(root_dir, ".svn"))):
-        root_dir = os.path.dirname(root_dir)
+      root_dir = current_dir = os.path.dirname(fullname)
+      while current_dir != os.path.dirname(current_dir):
+        if (os.path.exists(os.path.join(current_dir, ".git")) or
+            os.path.exists(os.path.join(current_dir, ".hg")) or
+            os.path.exists(os.path.join(current_dir, ".svn"))):
+          root_dir = current_dir
+        current_dir = os.path.dirname(current_dir)
 
       if (os.path.exists(os.path.join(root_dir, ".git")) or
           os.path.exists(os.path.join(root_dir, ".hg")) or