Fixing CVLFAB-716, an issue where the passphraseDialog and
the CreateNewKeyDialog were hidden behind the progress dialog
on Mac OS X.  The old method of obtaining the progress dialog
in order to temporarily hide it was broken, because it assumed
that the progress dialog was a property of the passphraseDialog's
parent window (the LauncherMainFrame object).  But this is no
longer the case.  So now the progressDialog is explicitly
passed into the passphraseDialog and CreateNewKeyDialog's
__init__ methods.