Make tab completion work for `cd C:\Users` (add `'` automatically)

[certik]

~$ cd C:\Users
cd: C:Users: Not a directory
~$ cd C:/Users
C:/Users$

Also, even when I did cd C:/Users, it should canonicalize the path, which on Windows we should print it as C:\Users.

The solution might need to be to hit tab and it will automatically escape using quotes: cd 'C:\Users'.