Refractor: Path Add utility unixify #478

Basically unixify all before workingm then transofom in function os os

Util: Add function sort_len that a list of string according to the lenght of its content
Fix: VimwikiRenameLink doesn't update links in diary #90
Test: VimwikiRenameLink with nested directories
Prettify comments in autoload/path + remove antipattern
Define osxify function helper to solve windows Vs Unix : see #478
Path: remove useless temporary fix convertion before calling relpath (redundant) : see #478
Test: Fix typo
Path corrected (Thanks to test)

doc/vimwiki.txt

@@ -808,7 +808,7 @@ Vimwiki file.
     The status of parents is updated accordingly.
     If you want to remove only items of the current nesting level, (re)define
     a command that calls the same function with `0` as first argument: >
-        :command! -buffer -range VimwikiRemoveDone call 
+        :command! -buffer -range VimwikiRemoveDone call
            \ vimwiki#lst#remove_done(0, "<range>", <line1>, <line2>)
 <
 *:VimwikiNextTask*
@@ -3675,6 +3675,7 @@ Contributors and their Github usernames in roughly chronological order:
     - Rafael Castillo (@eltrufas)
     - Reiner Herrmann (@reinerh)
 
+
 ==============================================================================
 16. Changelog                                              *vimwiki-changelog*