[Boa Constr] Boa files modified to support -s command line switch

[Patrick K. O'B. <po...@or...>]

Attached are three modified files. (I'm pretty sure I started with the
latest versions - Boa 0.0.9) The files have been changed to allow the
command line switch -s to execute the PYTHONSTARTUP (or BOASTARTUP) script
when Boa starts, just like IDLE. The key thing is that the startup scripts
need to execute in the shell interpreter's namespace. I borrowed the basic
technique from IDLE and modified it to fit the coding conventions used in
Boa.

These changes were tested with a good startup script as well as one that had
an error. Boa loads gracefully in either case and reports the error if there
is one. I also tried it with the -D filename debugging option and the
startup stuff was ignored. I'm not sure why. I'll leave it up to Riaan to
decide if that is appropriate behavior or not. I did NOT test it with the -T
option.

One difference that I found between my implementation and IDLE's concerns
print statements within the startup script. In IDLE, print statements in the
startup script appear in the shell itself, whereas in Boa the same print
statements appear in the Python console. Again, I'll defer to Riaan on this
issue.

Here is an example of running Boa with the -s switch:

C:\Python21\python.exe C:\Code\boa\Boa.py -s

You can also run it from a Windows shortcut or menu (but not from a DOS
prompt) with just the following:

C:\Code\boa\Boa.py -s

If there is a better way to submit patches like this, please let me know. If
you think my code sucks, let me know that as well. <grin>

---
Patrick K. O'Brien
Orbtech
"I am, therefore I think."