A fix for a quirks in git diff output

Once again I've a problem with some file with space in their name. Apparently, git diff some time add tab in the --- and +++ line, as shown in this interactive session:

    $ git diff -M -C --no-prefix| sed 's/$/$/'
    diff --git IUT/canditature/presentation-canditature.tex IUT/canditature/presentation-canditature.tex$
    index a72e4e5..71d6c8b 100644$
    --- IUT/canditature/presentation-canditature.tex$
    +++ IUT/canditature/presentation-canditature.tex$
    @@ -2,6 +2,7 @@$
     \usetheme{Madrid}$
     \usecolortheme{default}$
     $
    +$
     \usepackage[french]{babel}$
     \usepackage{tikz}$
     \usetikzlibrary{shapes,arrows}$
    diff --git IUT/programme pedagogique national.org IUT/programme pedagogique national.org$
    index 7d67482..e336310 100644$
    --- IUT/programme pedagogique national.org	$
    +++ IUT/programme pedagogique national.org	$

So those tab need to be removed when they are present.

I also added tests on file with space in their name, to protect us from further problem with this.

By the way there is no rush, enjoy your holidays.