Improve back trace handling

Print the full backtrace including the values of all variables, for
improved diagnostic analysis.

Change-Id: Iffcaa08123599e3610cdc2e316627167bfff0f36
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

src/testlib/qtestcase.cpp

@@ -113,7 +113,7 @@ static void stackTrace()
     char cmd[512];
     qsnprintf(cmd, 512, "gdb --pid %d 2>/dev/null <<EOF\n"
                          "set prompt\n"
-                         "thread apply all where\n"
+                         "thread apply all where full\n"
                          "detach\n"
                          "quit\n"
                          "EOF\n",