[cdt-patch] MICommand escaped double quotes and backslash

["Alain Magloire" <alain@xxxxxxx>]

A discussion with keith, prompted this change:

 1- double quotes "  are always escaped \"
 2- and so are backslashes \ --> \\
 3- expressions containing spaces are surrounded by " ".

This will let:
  evaluating --> printf("hello world\n")

 -data-evaluate-espression "printf(\"hello world\\n\")"

work correctely