stackbuilder - wizard: Warn the user before deselecting dependency

Log Message:
-----------
Warn the user before deselecting dependency downloads.
Rank downloads after selection to ensure they get downloaded in the correct order.

Modified Files:
--------------
    wizard:
        App.cpp (r1.1 -> r1.2)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/App.cpp.diff?r1=1.1&r2=1.2)
        AppList.cpp (r1.2 -> r1.3)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/AppList.cpp.diff?r1=1.2&r2=1.3)
        AppSelectionPage.cpp (r1.2 -> r1.3)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/AppSelectionPage.cpp.diff?r1=1.2&r2=1.3)
    wizard/include:
        App.h (r1.1 -> r1.2)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/include/App.h.diff?r1=1.1&r2=1.2)
        AppList.h (r1.2 -> r1.3)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/include/AppList.h.diff?r1=1.2&r2=1.3)