Anaconda exception handling testing

[Vratislav Podzimek]

Today, I have pushed (to master branch) a patch that adds an easy way
for testing exception handling (and bug reporting) in Anaconda. It
utilizes unix signals and can be fired by sending SIGUSR1 signal to the
main anaconda process (there are usually two processes, main is the one
with the lower PID). Probably the easiest way to do that is running this
command from tty2 (or window #2 in tmux):

$ kill -USR1 `cat /var/run/anaconda.pid`

Please note that it may need some additional interaction with the GUI to
get the "An unhandled exception occured..." window, as unix signals are
processed only when Gtk.main loop runs some (re)action.

The underlaying code raises an exception in a separate thread and with a
stack containing non-ascii characters (worst case scenario designed from
the bugs in exception handling seen so far). It also produces a unique
stack trace so that new bug is filed every time exception handling and
bug reporting in anaconda is tested.

These changes apply to the next build of anaconda (IIRC
anaconda-18.9-1).

-- 
Vratislav Podzimek

Anaconda Rider | Red Hat, Inc. | Brno - Czech Republic