Fatal

Annoying

Under Gtk 1.1.2, and possibly 1.1.1 and 1.1.0, Tab is trapped and
signal propogation stopped by the combobox itself before it gets
to our handler. Thus using Tab to complete the command from the
system PATH directories doesn't work. On Gtk 1.1.3 and above this
is fixed, they use Mod1+Tab, and the functionality is restored.
The Escape key has also been assigned to the PATH complete, so
use that if Tab doesn't work.

If a command has an embedded space in the actual command, which should
be escaped, gRun splits it at the space and tries to launch the
fragment. Must try catch escaped chars.