[tex-live] Mention new microtype in TL13 news

[Bob Tennent]

 > As far as I understand the new version of microtype that comes with TL13
 > now enables microtype features for the xetex and luatex engines.

I tried this.  

With xelatex:

 ! Package microtype Error: The kerning feature only works with pdftex-1.40 or newer.

 ! Package microtype Error: Letterspacing currently doesn't work with xelatex.

With lualatex:

 ! LuaTeX error .../oberdiek.luatex.lua:55: 
   bad argument #1 to 'insert' (table expected, got nil) 

This was with

texmf-dist/doc/fonts/libertine/samples.tex

Bob T.