Merge branch 'feature/pb/dos2unix' into 'master'

dos2unix contents dos2unix and the required dos2unix tool

See merge request frama-c/frama-c!2896

configure.in

@@ -979,7 +979,7 @@ configure_library([LABLGTK],
 configure_tool([DOT],[dot],[dot not found: you should install GraphViz],no)
 
 configure_tool([UNIX2DOS],[unix2dos],
-               [unix2dos not found: you should install tofrodos],no)
+               [unix2dos not found: you should install dos2unix],no)
 
 plugin_use_external(tests,unix2dos)