stackbuilder - wizard: Ensure regkeys exist before writing values to

Log Message:
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Ensure regkeys exist before writing values to them

Modified Files:
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wizard:
DownloadPage.cpp (r1.10 -> r1.11)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/DownloadPage.cpp.diff?r1=1.10&r2=1.11)
ProxyDialog.cpp (r1.2 -> r1.3)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/ProxyDialog.cpp.diff?r1=1.2&r2=1.3)