fix pause, resume, abort management

fix pause, resume, abort management

  * check there is no more VALGRIND/ASAN report when
    - abort in a pause (inside an executed script or not)
    - resume or abort after a ctrl-C in a "while %t, end"

  * check there is no more prompt when resume a paused loop

  * another test:

    uicontrol("style", "pushbutton", "string", "Default", "position", [50 50 100 30], "callback", "disp(""Default"")");
    uicontrol("style", "pushbutton", "string", "Prioritary", "position", [50 100 100 30], "callback", "disp(""Prioritary"")", "Callback_Type", 10);

    while %t,end

    click on Proritary button have to display "Prioritary"
    click on Default have to display nothing
    then Ctrl-C
    "Default" have to be displayed,
    resume must not show the prompt and abort have to go out of the loop.

Change-Id: I7c8f2a1a0a60975e6b91ac5920a79771d94114fd