stackbuilder - wizard: Download using a sensible chunk size - 4Kb seems

Log Message:
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Download using a sensible chunk size - 4Kb seems to nicely saturate my DSL line. Also, cleanup the text on the installation page.

Modified Files:
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wizard:
App.cpp (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/App.cpp.diff?r1=1.3&r2=1.4)
DownloadPage.cpp (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/DownloadPage.cpp.diff?r1=1.3&r2=1.4)
InstallationPage.cpp (r1.2 -> r1.3)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/stackbuilder/wizard/InstallationPage.cpp.diff?r1=1.2&r2=1.3)