Merge branch 'nd/conditional-config-include' into next

Merge branch 'nd/conditional-config-include' into next

$GIT_DIR may in some cases be normalized with all symlinks resolved
while "gitdir" path expansion in the pattern does not receive the
same treatment, leading to incorrect mismatch.  This has been fixed.

* nd/conditional-config-include:
  config: resolve symlinks in conditional include's patterns
  path.c: and an option to call real_path() in expand_user_path()