Better formatting in types.h

* Only closing brace on line.
* Empty lines.
Extract utils/fs.c:win_get_file_attrs()

* Windows only.
* Obtains attributes of a file.
* Skips check for unmounted disks.
* Returns the attributes.
Don't check link target on removing dirs on Win

We want to remove the link, not files in the directory it points to.
Move is_dirent_targets_dir() to utils/fs.c

Uses dentry or path to check file type.  Returns non-zero for
directories, otherwise zero is returned.  Symbolic links are
dereferenced.

Was is_entry_dir() in commands_completion.c
Rename commands_completion.c:is_entry_exec()

To is_dirent_targets_exec() for consistency with
is_dirent_targets_dir().
Remove first argument of is_dirent_targets_dir()

It's effectively unused.
Consider trailing slash for symlinks in :filter

Thanks to filterfalse.
Add comments to types.h
Fix windows version of new code

Didn't compile.
Fix out of bounds access in highlight completion
Fix referencing "vifm.h" from modes/normal.c

Doesn't work without ".." on Windows (can be fixed in Makefile,
but it's too late, need to update all #include directives).
Merge branch 'fix-symlinked-dir-filtering'

Make :filter command consider trailing slash for symbolic links
that point to directories.

Thanks to filterfalse.

Also:

 * Reduce some duplication and improve formatting.
 * Fix compilation on Windows.