#6 Debugger frontend patch

[Maciej J. Woloszyk]

Hi,
I've been looking into writing QT based frontend for
SDL version of VBA centerd on the debugger GUI.
Unfortunately I've encountered some problems with
capturing VBA's output via QT's methods. After
some digging I found that the problem is the stdout
beeing buffered when process is started without
connection to the terminal. Simple fix is to set
stdout to nonbuffered mode on program startup.

The second problem (or rather a missing feature) is
the ability to break into debugger from outside without
need to press F11 (to make possible for user to just
_click_ the break button in GUI). To fix this I added
the signal handler catching SIGUSR1 - after this handler
executes the same piece of code that is executed after
pressing F11 which effectively braking it into debugger.

I hope someone else will find these changes usefull and
to the rest - it should be transparent.

M.

[Maciej J. Woloszyk]