[BeOS] commit - More little fixes.

[Christopher Plymire]

Bug Fixes:

* Fixed bug #504 -- Front end stays running with no docs
* Fixed bug #1062 -- Abi quits when user elects to "Cancel" the quit.

Note: Bug #1061 was fixed by the previous commit.

Files modified:
abi/src/af/xap/beos/xap_BeOSFrame.cpp

- Christopher