stackbuilder - wizard: Search the unpacked Mac download to find the

Log Message:
-----------
Search the unpacked Mac download to find the installer bundle. We cannot assume it has the same name as the download file because
that will get renamed to the product ID.

Modified Files:
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wizard:
App.cpp (r1.33 -> r1.34)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/App.cpp.diff?r1=1.33&r2=1.34)