Command Entry Dialog

When this wdiget is active, ANA commands can be typed into the command line
for immediate execution. A history of previous commands is accumulated in the
history text area. These can be recalled by clicking on one. A single click
causes the selection to appear in the command line where it can be modified
before actually being entered and executed. The usual X editing procedures
with the mouse are available. A quick double click will instead cause
immediate entry and execution.

The output from ANA commands will not appear in the history area. It will
appear in the terminal window that ANA was run from. The commands can also
be echoed in this area if you activate the "echo commands in output"
check box near the top of this widget. 

Note that while the ANA command is being executed, all Motif widgets are
normally paused. This could be for a long time depending on the request.
During this time, any mouse or key clicks are remembered (up to some
limit) and then executed after the command is finished. So avoid impatient
button pressing if you are waiting for a long task, you may get what you asked
for.

This interface is still under development. We will probably put the output
in a text window somewhere in the widget rather than in the terminal
window and add some options to save histories and preload the history area.
Suggestions are welcome.