Merge branch 'js/windows-dotgit'

On Windows, .git and optionally any files whose name starts with a
dot are now marked as hidden, with a core.hideDotFiles knob to
customize this behaviour.

* js/windows-dotgit:
  mingw: remove unnecessary definition
  mingw: introduce the 'core.hideDotFiles' setting

environment.c

@@ -64,6 +64,7 @@ int core_apply_sparse_checkout;
 int merge_log_config = -1;
 int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
 unsigned long pack_size_limit_cfg;
+enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 
 #ifndef PROTECT_HFS_DEFAULT
 #define PROTECT_HFS_DEFAULT 0