Fix hang on a lot of output from a program

Summary:
There is a bug in the Qt glib event loop leading to timers never being
able to deliver signals.

Work around this by disabling the glib event loop.

References:
http://lists.qt-project.org/pipermail/interest/2015-September/018846.html
https://bugreports.qt.io/browse/QTBUG-48344

Test plan:
From the referenced bug:
    Stefan Westerfeld 2010-03-10 11:40:24 UTC
    Running the following program within konsole:

        #include <stdio.h>

        int
        main()
        {
          for (int i = 0; i < 100000000; i++)
            {
              fprintf (stderr, "foo %d\n", i);
            }
        }

    leads to a freeze - not single message is printed - no reaction on
    return. Only after a long time (30 seconds) something happens.

    If I run the same program in an xterm, the messages are scrolling
    through, as I would expect from that kind of output.

Reviewers: #konsole, hindenburg

Reviewed By: #konsole, hindenburg

Subscribers: hindenburg...