stackbuilder - wizard: Improve error message handling for applist and

Log Message:
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Improve error message handling for applist and mirror list downloads

Modified Files:
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wizard:
App.cpp (r1.32 -> r1.33)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/App.cpp.diff?r1=1.32&r2=1.33)
AppList.cpp (r1.17 -> r1.18)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/AppList.cpp.diff?r1=1.17&r2=1.18)
MirrorList.cpp (r1.9 -> r1.10)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/MirrorList.cpp.diff?r1=1.9&r2=1.10)