[SHELL32] Shell Profile Folders fixes.

[SHELL32] Shell Profile Folders fixes.

- Fix a regression introduced in r65415 (1795a3bf) where the directory
  paths stored in "Windows\CurrentVersion\Explorer\User Shell Folders"
  were stored in expanded format instead of in unexpanded format:
  _SHGetDefaultValue() *MUST* return unexpanded paths by design!!

- Augment _SHExpandEnvironmentStrings() and _SHGetUserShellFolderPath()
  to take a user token handle to be able to correctly resolve/expand
  user-specific directory paths.

- Fix _SHExpandEnvironmentStrings() so that it always retrieve the
  correct current user / all-users directory paths by calling userenv
  functions, instead of hardcoding a broken logic. As a result this
  removes the "C:\Documents and Settings\SYSTEM" ghost directory we got
  during ReactOS installation.

- Delimit the changes with respect to Wine by #if(n)def __REACTOS__ .